Fun pranks if you have a Roommate, or share a Dorm

Remove the toilet seat from the toilet.
Put toothpaste(sticky, slimy toothpaste) on the toilet seat. Squish! Squish!
Get one of those boullion cubes, made for making soup, and put it in your buddy's showerhead. A broth bath first thing in the morning can be a real drag.
Every time you go to your mark's house, put a couple plastic forks, spoons, whatever in the silver ware drawer. Pretty soon they will empty it out and begin to think thay are nuts.
Staple the cuffs of roomie's pants together.
In the winter, place extremely large snowballs in front of the doors.
While your roommate is sleeping, place two or three RedHot candies between their teeth and lips. They will wake up with a terrible blister.
Put clear tape on your roomates eyes when they're sleeping, wake them up, and and ask if they feel all right.
Insert an extremely cheesy CD (preferably Barry Manilow or ABBA) into a friend's favorite CD case. Make sure that the Cd's look similar. After they unwittingly put the CD in without checking, watch their expressions as the room is filled with "Coppa Cabana". Continue to switch CD's as needed.
Take a mini-tape recorder and record the words "They're coming for you." Turn volume setting to whisper and press play as your friend sleeps. Hide somewhere inconspicuous.
If you want to piss off your room mate, flip their matress and re-make their bed, so that when they are really tired and just want to crash , they will have to flip their matress back over and make their bed again!
Pile all of the furniture in your dorm or house against someone's bedroom door. When they wake up in the moring, they can't get out!
Take some Oreo cookies. Undo the tops, one at a time, and place a small circle of wax paper in between the cookie and the filling. Then set them out to watch your victim take a big bite!
If your roommate has posters of scantily clad women up, blow up a picture of their mother's face and tape it over the face on the poster. Very disturbing for the victim.
Every day take a small object from another student's room and place it in a different room. Repeat until room is empty.
More instructions for shooting toilet water: Materials: 6" piece of small diameter tubing, 't' valve. Process: Remove the top lid of the toilet tank, the filler tube in the center of the tank has a samll tube from which it fills the bowl. Pull the tube out ot the filler, install the tvalve & the other end of tubing. put the bottom part of the tavalve back into the filler & redirect the new section of tubing pointing out at where the victims back will be when seated. Place the lid back on, being careful not to leave the tubing showing. When your mark flushes, the water will squirt out, trapping your mark & catching him/her by suprise in the small confines of the toilet stall. Been tried twice with excellent results. Even better if you can find one is to place a car washer jet on the outer end of the tube which fans the spray out.
Put white 'art' paper like the kind used in pep rallies over the outside of a dorm room doorway. You and your friends get up a little early to stand out in the hall and clap and cheer when the roomate who's in on the prank jumps through the paper (like a football game). The next day, repeat the procedure, placing a candy or drink machine behind the paper. When the 2nd roommate (who's not in on it) tries to burst through the paper for his/her applause, BOOM! S/He will hit the back of the machine and rebound back into the room.
Offer two of your friends marshmellows. Leave one of the marshmellows as is and make a little hole in the other. Pour salt and pepper in and close it up. Put them back in to their place and offer them.
When you see your friend sit down a can of soda, take a small knife or something sharp and poke a hole just below the the lip of the can. When the friend takes his/her next drink, soda will drip out of the can and onto the victim.
Take a large bottle of industial strength washing up liquid, this can be bought from any supermarket, and pour it in the top of the toilet (where the water is kept). When the victim flushes the toilet, the bowl and eventually the room will fill with lovely bubbles.
Tape down the button on the receiver of the telephone and call them.
Try the exploding salt and pepper shakers! Take the salt/pepper shaker and empty it about a third of the way, then fill the empty space with the lemon juice. After that put a tissue piece over the top and stick in down inside careful enough not to hit the lemon juice. Put a small or medium amount of baking soda in the tissues and cover the holes with something to keep the baking soda from coming out. Then stick the lid back on. Give it to someone you know will need to use it. When they shake lightly to get a little bit of salt, it will not come out. So what they do is shake harder, making the lemon juice break through the tissue, mixing with the baking. This causes the lid to somehow "explode", or pop off, and filling half the table with foam!
Offer your friend some really thirst provocing cookies. Then when they're really thirsty, hand them a glass of milk with a few of those mini-marshmallows in them. Whole milk works best. They'll have slugged back half of it by the time the marshmallows hit their lips. Watch the reaction of someone who thinks he just took a huge slug of curdled milk.
If your in the room when someone cuts their finger, tell them that lime juice is the best thing to stop the bleeding.
Fill a very large glass full of water, tell a friend to place their hands on a table (plams down), put the glass on top of one hand and ask if it hurts, when they say "no" tell them to put one hand on top of the other, place the glass on top of both hands and walk off.
Put a bit of baby oil into somones bottle of shampoo. Why is my hair always oily?
Smear Icy-Hot all over the toilet seat. When someone sits down they'll feel the cream working.
Put a life-like real sized cardboard figure of a person in the bed under the covers next to the victim. Imagine the shock when they wake up!
Put crazy glue in someone's shoes so when they try to take them off, it gets stuck to their socks; or better yet, their feet.
Get a camera with a flash and a cap gun. Early in the morning, like around 2 o'clock, knock on peoples' doors. When they answer the door, take their picture and then shoot the cap gun. The flash stuns them and they think they've been shot.
The last person to wake up in the morning gets it. Get a game going; each awake person takes a turn decorating the sleeper, using their imagination (spitwads, beer cans, paint, figurines of Elwood Blues tucked under the elbow.)The first person to wake the sleeper up loses while everyone laughs at the victims reation.
Send in the victim's name as being interested in joining the navy, air force, marines, coast guard, etc.
Get a Universal Remote and go to the window of someone watching TV and change channels.
Take a really large pair of underwear old lady or man style and write a victim's name in them and leave them in the bathroom floor for every one to find.
Put a vacuum cleaner with the switch in the 'on' position in someone's room in the middle of the night and plug it in out in the hall.
Get a pair of old boots, put them on the floor in the toilet to make it look like someone is sitting on the toilet. Then lock the toilet door. Works best if there is only one toilet. Watch people repeatedly walk in and them come straight out again. Particularly works well after lunch or morning tea.
Tell someone that you will give them $100 if you can crack 3 eggs over their head. After getting them to agree, crack 2 over their head. make sure to rub in all of the yolk. Then tell them you don't feel like cracking the third egg. Now you don't owe them $100.
Chilli sauce on the rim of a coffee mug. Imagine how hard it would be to have a mouthfull of hot coffee and have burning lips too!
Whenever there are grapes in the fridge, be sure to put one on top of every bottle, tupperware container, dish, can, etc. EVERYthing must have a grape on top of it. After the second round of "grapes on bottles" the victim's failure to see the humor will manifest.
Put Ambesol (toothache reliever) on the victim's retainer when they aren't wearing it. Their mouth will go numb.
Straighten out a small staple and tap it all the way down into your roomates deodorant. After several days, they'll start to feel a small scratch followed by an intense burning sensation (as the deodorant gets into the scratch) From that point on it's fun to listen in every morning until they realize why it's so painful.
Get a long piece of chemistry tubing. Tie one end with a knot and fill it with water. Get a couple of guys to carry it to someone's room and stick the open end under the door. Instant flood!
Do you know a deep sleeper? Gather a few friends and pick up the deep sleeper's bed and carry it into the quad in the middle of campus. Hopefully, he won't awake until there are people all around him. Extra laughs come when he sleeps, well, pajamaless.
First, you need to find a cow. Transport the mellow beast to the multistory-dorm of your choice. Lead the cow right on upstairs to the top floor. Give the cow some hay or grain (also useful to lead the cow...) and water. Wait for the fun to begin. When officialdom appears and starts to "take charge" of the situation, they will find that while a cow will readily go *up* the stairs, no power on earth will induce a cow to go *down* the stairs.
When staying at a hotel, tell the front desk clerk you need a 4:00am wake up call. Tell him/her to let the phone ring repeatedly as you are a very heavy sleeper. Then give the clerk the room number for your friends across the hall.
If you have co-ed bathrooms that have free comdoms and lubricant packets (water based), smear the stuff all over a wall in the hall. It's not shiny at all, so it's really hard to see. Expect people to bump against it and get "jizzed."
Put icy-hot in your neighbor's shampoo bottle...Why is my head burning??
Set off a fire drill in the middle of the night by putting a cigarette close to a smoke alarm. The real fun in this is that you get to see who's sleeping with whom.
Tell everyone in the dorm that you've gotten a care package from home, and you want to share. Offer them Ex-lax brownies.
Use this if you know the people inside a room or dorm room has no other way out. You take about two rolls of duct tape and make a duct tape wall so that the entire door frame plus about another foot of area outside the door frame will be covered with duct tape. To make the wall you must inter lace the duct tape to make it stronger. Needless to say, the victim will have difficulties getting out.
The next time you have a party be sure to stock up on super glue. When the victim falls asleep put the super glue on their zipper of their pants.
The Bathroom Bomb: The trick is to happen upon some poor shmuck in a stall when you go into the little cowboy's room. Don't say anything or make any tell-tale noises that might give your identity away. Get about a yard of paper towel from the dispenser, crumple it up, and get it really wet. Make sure it is really dripping. Now, you can either lob it grenade-style over the door and onto his lap/head/whatever, or, with practice (tough angle) you can stick it to the ceiling above your targets head. It will drip down on him and eventually peel off and land on his head. He will be helpless to move out of the way, considering what he is doing.
During the week or so that the biology students are mutating fruit flies, spread the rumor that water works just good as oil in killing off your fruit flies. In reality they just escape from the water and swarm everywhere. Someone is bound to believe you and try to save money by drowning them in thier dorm sink.
Take a dorm door off it's hinges and put police tape on the hole where it used to be.
Put a sign that says "Janitor's Closet" over someone's dorm. Then dress up like a janitor and knock constantly asking for trashbags or disinfectant.
Hide many different alarm clocks throughout the victim's room and set them all for different times.
If your planning on leaving for the weekend, set your alarm to go off automatically every morning at 5:00 am, and lock your door.
Knock on the dorm door a couple times and run. Repeat a couple times. Tell your 'buddie' that you can't seem to knock loud enough for the people to come out and have him knock on the door and stand there.
Go to a beverage center. Ask for a free cardboard box (the low-cut kind). Find a bait shop. Buy a couple containers of earthworms. Close windows in the target's dorm room and turn off the air conditioning. Put the worms in the box. Put the box up high (on top of a shelf). In a couple days the place will smell like a dead body. Works best in summer.
Dare someone to try and drink six full glasses of water. Little do they know that the bathroom will be occupied by your friend (or is that a mannequin?) the whole night.
For a sticky shower, unscrew showerhead that your evil roommate showers in and put a piece of hard candy in there. Replace head and don't forget to avoid the shower. Yellow Jolly Ranchers work well and don't change the water's color.
If the building is heated by a hot water system, throw grass seed on the floor during the Christmas break in winter and when the roomate cames back after the winter break there will be a lawn in the room!
Reset his or her alarm to the early morning.
Buy (or make) one of those wallets that flare up inside when opened and replace it with your roommates wallet.
Rip a few KEY pages out of a bud's textbook right before finals and hang them around the dorm.
Take Kool-Aid packets and pour little strands of Kool-Aid on your roommate's sheets. When the victim sleeps they will sweat. And when they sweat, the kool aid will get in their pores and they will be colored.
While the victim sleeps, remove any containers of milk that they may have in the fridge. Proceed to add an entire container of finely ground hot pepper to the coffee grounds in their automatic coffee maker. They are out of luck after sipping their cup of java the next morning, because the only liquid that doesn't make the hot pepper worse is, of course, milk.
While your victim is out, replace the legs of his bed with empty "Bud" bottles. Pull his sheets so they drape over the side of the bed (restricting the bottles from his view). Crash!
While your roommate is sleeping, sprinkle fake insects all over them (gooey and slimey ones too!). Wake 'em up.
Paint a roommate's face while they sleep. When they wake up they will wonder why everyone is looking at them and laughing. HaHaHa!
Replace sugar in sugar bowl with an antacid. When someone goes to put sugar in their coffee it will foam up and out of the cup.
Put bubble gum behind the wheels of a chair.
Superglue the handle of a toolbox to the top.
Hide all the extra rolls of toilet paper and glue the last together. What creative idea can they use to wipe?
Wet your hands. Go behind an unsuspecting person and pretend to sneeze loudly. Then wipe your wet hands on the back of the victim.
Put Nair on a man's legs while he is asleep or if you're really mean, put it on their head or in their shampoo. Call him Baldy or Slick when it's over!
Place shaving creme in the hand of one who is sleeping. Tickle their face and watch them slap their face. They'll wake in a state of terror.
During winter time in any part of the country where it gets really cold, take your victims mattress, soak in water until it has reached it's saturation level, then hang it outside until it freezes solid. Once solid, replace on the victim's bed and make the bed up to look like normal. Brrr...
Fasten a sound module from the crying baby dolls to the bottom of someone's chair. Is there a baby crying?
Wait till your victim is away for a weekend. Dip everything plastic (pens, phones, etc.) in liquid nitrogen, break it, and stick it together again. Everything plastic will break when he picks it up.
During a family dinner, keep an empty jug of water on the table. When somebody asks you to pass the jug, pretend it is full of water and heavy. The victim will apply what he considers is the appropriate strength needed to pick up the jug. This will cause the jug to jerk up to a significant height. Maybe they'll fall off their chair!
If you live in a dorm with tiles on the bathroom door, pour rubbing alcohol in the cracks, wait for your victim to go into the bathroom and seat himself. Light it. (Be sure to keep a fire extinguisher around.) Add some evil sounds for more effect.
Place your sleeping friend's hand in a bowl of warm water. WeeWee!
Cover the door handel with something sticky such as ketchup, dog doo, or glue. What type of creative method will they try to open the door?
Slip something red in with a friend's white load of laundry at the dorm laudromat... PINK UNDIES!
Put shaving cream in the tips of someone's shoes. It'll squirt out at the ankle if you have enough in.
Turn an overhead projector on and place it so that the light is facing a closed door. Whoever opens it will be greated with a flood of light. Works great when a bud has a hangover!
If you're going home to visit the family, cover your body with temporary tattoos the day before.
Put Suran wrap over the toilet bowl but under the seat. It'll catch it all!
Don't just short sheet the bed next time, add Corn Flakes between the matress and sheets too.
Dump a whole bottle of detergent into the toilet tank. This produces great billowing suds out of the bowl on first flush. Especially great if first flusher is sitting at the time. OooWee!
Put baby powder inside a friend's hair dryer. They'll smell AND make a mess.
Sprinkle finely ground powdered milk underneath your victim's sheets. It acts like powdered sugar in the sense that, as you sweat in your sleep, it dissolves and comes up through the sheets onto your body and into your pores. But your sweat makes it sour, and when it gets into your pores, it stays there. You smell very strongly of sour milk for about a week.
Take one of those musical greeting cards rip out the part that actually plays the music. This is only about the size of a quarter. When the victim isn't watching, plant this somewhere near them. Since it is so small, it is relatively easy to hide in a pocket or a purse.
Put goldfish in all the toilets. Where did they come from?
Go into the bathroom while the victim is taking a shower, and pour a bucket of REALLY cold water over the top of the shower curtain.
Get a LOT of condom wrappers and put them in the bathroom garbage can while your male friend kicks you out for that romantic dinner with his girl. Slap...
Replace a guys undies (especially briefs) with ones one or two sizes too small. Itch...
While the victim is asleep carefully put Vaseline between their toes. The person's toes will start to wiggle. The apparent mechanism is that when your toes start slipping against each other, your mind insists on making them slip and slide more and more. The upshot of this is that the part of the mind that's supposed to be getting rest is busy moving toes. The victim 'wakes up' having had no sleep at all.
Put cherry Kool-aid in the shower head. Is that blood coming from the shower head?
Get some of those mini-firecrackers that you can throw and they will pop. Put some on the toilet seat or on the edges of drawers for a scare.
Place a knife with ketchup on it on the victim's bed to make it look like it was the scene of a murder.
Turn all the pictures and posters upside down. Another test of their sanity...
If your victim is your roommate, switch the material in your waste baskets and pull his bed away from the wall a quarter of an inch every day. Sanity test...
Cut hair off of a doll and place it on the victim's bed. Nickname them after thier loss of hair.
For faucets with an optional squirt hose, rubber band the trigger down.
Obtain a large cellulose sponge, trim to make sure it is about 1/2" thick. Make sure edges are rounded to an other than square shape. Offer to cook dinner. Chicken fry the sponge.
Soak a roommates underware in water and tie it to things in the freezer (or outside if it's winter). This can be compounded by the option of house sitting during their vacation. If you do this to the underware in their drawer, they will only have dirty undies from the vacation to wear. Ewww...
Fill a small box with the punch-holes from paper tapes. Remove the bottom and place it on a bookshelf. The victim will pick it up letting all the holes everywhere. Simple but sweet.
While your friend is sleeping, carefully water down his mattress.
When the victim is sleeping, make a shallow paper tray and tape it to his door and to the door frame near the knob. Fill it with unpopped popcorn. When he opens the door (from the inside, obviously) he'll have popcorn flung all over the place. Tough on the vaccum too.
If the victim uses Head 'n Shoulders or Selsun Blue shampoo, and a few drops of methylene blue (available in pet stores) to a full bottle. Over time (if the victim is fair-haired), you will notice their hair turning BLUE, as methylene blue stains all organic material.
Buy a teddy bear with one of the 'buttons' manufacturers put in them to make the sound or music play. Tear it out and place it in the victim's pillowcase. Is it a dream?
Take their stuffed animals, soak them in water and put them in the freezer.
Make the cook of the house mad and peel all the labels off the canned foods in the pantry.
Prior to trapping the victim in their room by some creative method, plant a cellular phone that has had its keypad disconnected. Needless to say, keep calling!
While your dormate is asleep in bed sneak into his room and cover his entire floor with dixie cups that have been filled with water. Make sure you cover the entire floor not leaving any room to walk, when they wake up they will have no choice but to drink their way out.
While dormee is in room with door closed take a grocery sack which has had some flour poured in it and crease the opening so that it can be slipped under the door. Once it has been slipped under the door jump on the bottom of the bag sending flour all over their room.
At lunch, get some butter and a glass. Put the butter on the bottom of the glass and stick it, butterside up, to the bottom of the table. As soon as you do this, walk away from the table. Hopefully, someone will sit at the table. When they sit to eat, the butter will melt and the glass will fall.
Make a small, off-center hole in a can of shaving cream and then heave the can into the victims open door. As the pressure spews the cream out, it will spin the can and create a real mess.
Polish the floor and stick teflon to the legs of select items of furniture.
Butter all of the toilet seats and/or doorknobs in your wing of the residence. SlipSlip...
Get a lightbulb and remove the wire. Fill it up with Corn Flakes and flour. Hang it by a pulley and attach the rope to the door. When they open the door it will drop like a bomb. Be prepared to clean up...
Enter subscriptions in a neighbor's name to some filthy homo/bondage magazines you can find, and change his address by one so that another neighbor receives them. :)
For a pair of roommates, switch all or their possesions.
Tape together a bunch of sheets of newspaper to cover the victim's doorframe. Then tape a big sheet over the doorframe and leave a gap of about two or three inches between the sheet and the door. Fill the gap with paper balls right to the top of the doorway. The victim will be showered with a barrage of paper balls. Obviously, the door has to swing in for this to work.
While someone is in the shower, take all their clothes and his towel and hang them outside. TeeHee...
When someone goes into the bathroom (or another room with a door that must be pushed open), tie one end of a rope or chain to the outside doorknob, and the other end to a fixed object like a dishwasher.
After making sure that the victim is out or sound asleep (if the victim is in make sure he can't get out), put a line of baby powder along the bottom crack of the door (or on a piece of paper and slide it under the door). Then use the blow dryer to spray the powder into a fine mist that will cover everything in the room. Messy...
Kidnap some small beloved object (teddy bear, etc.) or some embarrassing possesion of the victim (underwear, etc.). Once its owner has noticed it's gone, suspend it from a window in the dining hall, TV lounge, physics building, whatever.
Distribute a roommate's furniture throughout campus. Good reactions from everybody.
Once you have stolen a dormmate's room keys, reverse the lock (so the keyhole faces INTO the room). Then loudly announce to the victim you own the keys, but 'let' them win the race back to their room. Fix the phone to continually ring for an added effect.
Collect and stack a bunch of beer or coke bottles (make sure that they are glass) right in front of their door. Ring the door bell late at night so the occupants open the door and knock down the bottles. Crash...
If you have a week, fill a room with crumpled up newspaper or popcorn.
Pour vinegar in the open baking soda box and close the door. Mount Saint Whirlpool will erupt. Messy...
Put dry ice in the dish washer or washing machine and set the dial to 'Rinse.' Mount Saint Whirlpool will erupt again.
Take an old record album cover. Fill the insides with shaving cream and place it halfway under a locked door to the victim's room with the open end inside the room and jump on it. Messy...
Take someone's door and hide it for a while. You get great reactions from this one. They may not care at first but what happens when they want some privacy?
Subscribe your neighbor to a zillion different trial magazines. Especially ones that they wouldn't even dream to subscibing to.
When your victim is in their room, push on the door so that you can fit a penny between the door frame and the door. They'll be stuck!
Tie a string to the fire alarm's handle and neighbor's door. Knock on the door. DingDingDing...
Tie one end of a rope to someone's doorknob and tie other end to a doorknob across hall. Neither party will be able to leave their room. How long will they be able to bear their roommate?
In the winter, put a nice layer of water on the dorm floor and leave the windows open.
Get a few buds and tape a person up. Then leave. Packing tape works best and doesn't hurt THAT much when you rip it off. :)
Wait until lat on a school night. Get a friend and set up the room to look as if the two of you are busy studying for a test. Turn on some classical music at a low volume. Then, on que, begin jumping up and down and banging chairs against the floor. Your dormmates living directly below you will go ballistic. After about 30 seconds, stop and return to 'studying'. The downstairs neighbors will come up to find out what's going on. What noise? Wait five minutes and call them (hang-up call) to make sure that they are in their room. Then, repeat the process as many times. When you open your door, they should be sure by then that you are the culprit. Offer to help them find the culprit (this will really throw them off). Of course, YOU haven't heard anything, so they will most likely refuse. Repeat this prank periodically for maximum effect. The victim may begin to question their sanity.
In the early A.M. hours while it is still dark borrow something noticable from the house across the street. Put it in your victim's yard.
Leave old trash paperbacks around launderettes and other public places. Write inside the front cover: Property of Victim. I need this book for my thesis. If found, please return to address for a $50 reward.
Post ads around town for a garage sale at an unexpected person's house.
Get a somewhat long spool of rope, and when walking down the street (acting official), get someone to assist you in measuring a distance. Pick a spot near a corner, go around, and find another person to hold the other end of the rope.
Put a paper bag with dog doo on the person's front step and set it on fire. Knock on the door. The victim will stomp it out.
Fill a plastic garbage bag with water, shaving cream, cologne, etc., until it's about 1/2 full. Place it right next to someone's door. When they break the bag when they open the door, be prepared to help clean up. Real smelly. :)
Remove everything from someone's room and set it up somewhere else exactly as it was. Try moving it to the roof of a building, front courtyard of the residence, or in the dining hall. How'd that get there?
Cover the doorway with paper, just paper. Let the victim open the door, find the paper, and break it all down. Do this as many times as you wish. The next time, paper the door and either place bricks or a trash can behind the door. By this time, he should just walk through the paper. Donk...
Take a plastic 35mm film canister, paper punch-holes and a can of freeze spray (at fine electronics stores everywhere). Fill the film canister with about 1/4" of freeze spray then add punch-holes until the film canister is at least half full, replace the lid on the canister. Set the canister on a desk or shelf. When the canister pops it shoots paper all over the area. Different amounts of liquid causes it to pop at different times. Fun to fool around with.
Remove the drain pipe from the sink and put a bucket of water balanced above the door, ready to fall on him when he opens the door. They're too smart too fall for the old Bucket-On-Top-Of-The-Door gag, so they take it and empty it into their sink. :)
Shred about 5 complete newspapers and put them in a 5 gallon bucket of hot water. Pour it on the victim's lawn. If they try to wash it out it will stick to the grass. If they let it dry and try to use a lawnmower to get it out, it will cling to the grass.
Thanks to Pavlov, we know know about a reflex reaction caused by a continual stimulus and some conditioning. Now, somehow get a talking parrot and a grandfather clock. Try to babysit your friend's parrot or give him one as a gift. Now, make sure they have a clock that goes off on the hour (ie. Grandfather). Train the bird so that every night at midnight when the stiumulus (clock) goes off it will say: "I've come for your soul." You have to keep the bird in the dark and only say it once! Give the parrot to the victim and watch his tired face.
Get syringe without the needle and mix it with epoxy and rubbing alcohol. Now, within 30 minutes, fill a door crack or any thing else you want to stay in place.
Armor-All is only visible when sprayed on concrete (and dried) during a rainstorm (or lawnsprinkler). You can then write all you want about friends all over the neighborhood. It lasts for a good couple of rain storms.
Glue a quarter to the sidewalk.
Go into somebody's home and turn everything in the fridge upside down. They'll wonder about their sanity.
Write "SEX" as big as you can with Vaseline in someone's bathroom on their mirror. For double the pleasure outline it with toothpaste.
Epoxy glue doesn't dry without the hardener; it just stays sticky. So, be creative with it. Try the toilet seat, doorknobs, etc.. Since it can be washed off, the victim will usually visit the sink. Put some on the faucets, too.
To really smell up and smoke a person's room, put Limburger cheeseon a radiator.
Catch live frogs or toads and put them in mailboxes.