I've been having a look at this site/app recently:
http://www.impossible.com/Basically it works by people posting "wishes" that others can commit to working on or helping with. The aim ultimately is for it to help with social economics; in other words, people gaining by doing things for each other for free. It's a really neat concept and is backed by Jimmy Wales (of Wikipedia fame) and Lily Cole (actress & model, also got a double first or something similarly brilliant from my own dear Uni).
There are some issues - mostly people not understanding the concept and being like "give me an xbox lol", or at the other end being more on the lines of "I wish for smiles and love and rainbows". That said I think it has a lot of potential, though to be really effective the network probably needs a higher density of people. It seems to be most effective around London, for probably obvious reasons as that's where they're based.
I also just wished that more people would find this place, so we'll see how that goes.
