You seen this yet? Bitcoins. It's virtual money, circulated digitally, issued by no government, and open-source.
People have been saying since the beginning of time that money has value only in the abstract and here is proof of that. A Bitcoins' value lies in the trust that the receiver puts in it. There's no gold standard, silver certificate, or Fort Knox. If the current regime you are living under fails, you can't melt it down and redeem it on the gold market. But then, there is no current regime when it comes to Bitcoins.
It'll be interesting to see if this takes off as fast as Paypal did. It might could even put Paypal out of business.
Right now there's not a whole lot on the list of places to use your bitcoins, but I imagine that will change.