The concept is actually nothing new really. It sounds good then you think about, but it's hard to be able to view every angle at one time.
The act of doing something in return for something else is not that much different then the use of money when you think about it. When you sell something or do something for money, you do it becuase you know that money can buy you the material good that you need or want. So basically you're still trading one object for another. However, money simply provides a system that makes things smoother and more convenient.
Also, how would you pay for the fixed costs of living in modern society, such as electricity? I also agree with Dave, someone who is disabled would have a hard time surviving unless people really did help out of kindness.
Perhaps in a perfect world, but I just couldn't see it happening. The truth is, humans are not a bunch of goody two-shoes, unfortunetly. We all have greed and lusts for material goods, and the primitive side of all humans are selfish bastards, to put it bluntly. It's not the nature that is around us, but the nature that's within every one of us.
Good concept and a good read though.
