Looking for a low buck power steering cooler? 

If you're running big tires on your 4x4 and do lots of slow, technical trails that require you to constantly be turning the wheel to line up with the next obstacle, then you are most likely overtaxing the factory power steering system.  The fluid can overheat, shortening the life of the power steering pump, seals, and gearbox.  Here's a cheap solution to the problem, and it's probably available in nearly any junkyard in America.

Start by checking early 90's front-wheel-drive Cadillac's in the junkyards.  They use a nice, 2-pass tube and fin cooler, about 10 inches long, right from the factory.  They even come with a nice mounting bracket.  You'll find it mounted to the core support, just behind the grille.  If you want to bother with removing the clamps that hold the rubber lines, you can even get several feet of that as well.  I paid a whopping $3.99 for this one at a pick-n-pull yard:
 

Clean it out good with some solvent first.  Then mount it in front of the radiator and plumb it into the return side of your power steering system to keep the fluid nice and cool.

Here's a couple of shots of it installed on my '90 Suburban.  It's on the bottom left, just under the transmission cooler.   I used a tubing bender to bend the short tube 180 degrees so that both of the lines run towards the steering box.

I really like the "double" hose clamps that GM used on these.   They have a small bar spot welded between them to keep the spacing correct.