
Being raised in our society it can be hard to think that things could be any different than they are. It's easy to think our screwed-up behavior towards each other is an immutable characteristic of fundamental human nature.
However, as convincing as the "human nature" argument seems to be to so many people (it is invariably used whenever I talk to about radical transformation of society, and usually delivered with a sort of "bet you never thought about that, eh? can't argue with that, can ya?" arrogance that still surprises me every time I witness it), it is quite a claim to make. If greed and power-grubbing are aspects of human nature, then they are our nature. They cannot be changed. They must govern our behavior.

Of course, this is demonstrably untrue. The entire practice of friendship is evidence against it. Friends sleep at each other's homes--yet no one asks them for rent. Personally, I nearly always see the homeowners' dishes get done over the course of having friends over, with nothing beyond a polite request (or even no request at all). When a friend really needs something, only a true asshole won't offer to help them out. These things don't happen because anyone takes a position of authority to force them to. These things happen because the people involved want to, because helping each other out isn't an alien concept to people. It's just that at the moment we have all been placed into a context where success and helping people out are, if not mutually exclusive, close enough to it.
Economics based on the free giving of gifts to the people in your life has historically been given the name "mutual aid". More recently people have started to call it "gift economy". But whatever name is given to it, it means this: Help out other people when you can, accept other people's help when you can't. Economics where it's safe to rely on each other.
Lest you think I believe people to be "naturally good" (an equally, if not more, foolish argument than the "naturally evil" formula), this is not what I am implying. I am simply implying that if people are put into an economic structure in which helping people out is not a handicap to your success (and, indeed, is the best way to expand the group of people who are into helping you out--nobody likes all-take-no-give), then they'll do it. Not because people are inherently good. If that were true, screwing other people over would be a perversion and not the rule, no matter what system we lived in. Rather, because I don't think most people are bad on purpose, without motivation.
The people I talk to who most swear on the gospel of people being evil are also the people who are sheltered. By this I don't mean that they are necessarily rich, but that they live with their parents and have food and shelter provided for them. I know when I had never really been out into the world I thought people were, on the whole, bad.

While hitchhiking around broke in the summer, I found it difficult to reconcile that opinion with the uncountable experiences I had of strangers offering me rides, food, money, and places to stay.
My position is that these offerings of aid and gifts should come to form the bulk of our economic activity. This isn't wishy-washy hippie stuff. I'm not suggesting we should love everyone like brothers and sisters. I'm simply suggesting that it's not unreasonable to think that people can relate to each other in ways other than they do right now. And we should try do to so more often.
Beyond "share what ya got" economics, of course, there is the matter of organizing the productive activities that need to be done to sustain life. We all need food and water and a roof over our heads. How are we going to provide ourselves with these things without the hierarchy and authoritarianism of the systems of ownership I have outlined earlier?
I think the answer is voluntary cooperation.
Organization doesn't have to based on authority and hierarchy.

There are examples of this even today, and they aren't all dysfunctional hippie communes where those involved smoke pot while the dirty dishes pile up in the sink and the toilets overflow in the bathrooms. Many groups organized around non-hierarchical principles actually get stuff done. Food Not Bombs, for example, is an entirely decentralized group with autonomous cells operating all over the country. Within these autonomous cells, there are no officers elected or orders given; rather, the people involved cooperate on a voluntary basis to get free food prepared and served in public spaces to provide hungry people with stuff to eat. The local pirate radio station in my town is similar in that no one is a position to give orders, and people determine their own level of involvement. People contribute their time and money to pay the rent and electricity and get the paperwork done and the trash taken out...but no one is forced to any of it.

My hope is that these kinds of groups can form the norm, instead of the exception, of the way people get necessary things done. When you have people involved with a project that is truly important to them (and you can bet that stuff like getting food to eat will be important to people!), they don't need bosses to make them do it. They'll get what needs to be done finished by working it out with themselves.
Sure, bad stuff will happen sometimes. Bad stuff always happens. Things will get stolen, people will get killed, drifters will drink too much whiskey and throw up all over the beds of their hosts. At the moment we trade the autonomy and equality we could enjoy as a species to the structures of state and capitalism because supposedly these systems are to save us from having those things happen to us. The thing to ask yourself is: are you willing to trade a society where you and the people you love have the freedom to pursue the things that bring them joy for structures that fail to protect us against the horrors they justify their existence on?
I am not willing to do that, but that choice is one we all have to make for ourselves.