The idea is simple: to have an internet-virtual currency, for paying for products and services that goes around internet, that don't mean moving phisical things in the real world.
The widest way to pay for that kind of things now in internet are credit cards. Worldwide credit cards are relatively few, and not accesible for really everyone. Maybe Paypal could go around this idea, but don't know it enough and maybe not.
The idea is to have an easy way to have a virtual interchange way for doing "virtual" thing, being download mp3, access ebooks, registering domains, etc, no phisical goods involved, but things that can be transfered or used thru internet. You can earn them with donations, posting banners, doing some real work (translate things, writing programs, the old google invites, hosting files, etc), but the critical point here is that real money is not obligatory (maybe the system could be enritched having some way of interchange between virtual and real money)
For this to work should be internet wide and try to be something unique and not tied with a commercial company, but maybe to an international organization (UN?) or standards body (something like ietf, w3c or things like that)
Of course, 2 questions remains for me: Have this some internal contradiction that make it impossible? Exist already something like this?