I just found this out and it actually looks like P2P revolution. I haven't tried it yet and it is only a beta version but what I have read sounds really promising.
The program I am talking about is OMEMO http://www.omemo.com/
It has a completely revolutionary look on P2P file exchange. It creates something like a virtual shared Internet hard drive. When you install the program you have to share part of your hard disk with the world (I don't know how much). The difference with other systems is that you are not sharing archives but the space. In fact you don't even know what is on your hard disk because each file that is upped to the program is chopped in 64k pieces which are encrypted and then distributed among different PCs. The good thing about that is that there is no way to know who upped anything or even no way to know who is downloading what (at least the authors say they don't know any way of doing that).
The files that are uploaded can never be deleted, not even by the uploader but there is a rating system that I suppose allows not to keep too many copies of files that nobody wants. The rating system is based on positive/negative votes and each delete counts as a negative vote.
And the best of all is that as far as I understood the program is open source!!!
All of this information is unconfirmed and taken out of a Spanish article (the program is Spanish) so apply for a beta tester (the program is still not on the net),try it and tell us your experience. I'm going to apply right now.