Paper IOUs seem almost ideal, if we didn't have to rely on a central issuing authority to make them universally accepted. IOUs are easy to replicate with blind

Paper IOUs seem almost ideal, if we didn't have to rely on a central issuing authority to make them universally accepted. IOUs are easy to replicate with blind signatures (see Section 4, Examples: http://web.mit.edu/6.857/OldStuff/Fall02/handouts/L15-voting.pdf http://web.mit.edu/6.857/OldStuff/Fall02/handouts/L15-voting... ) but noone wants to hunt down as many people as they have bills, just to trade the individually-issued digital IOUs... This is what Ripple ( http://ripple.com http://ripple.com ) claims to do, though: act as a distributed clearing house to resolve and cancel debt via a social graph. I haven't had a chance to actually use Ripple though, so I am certainly not recommending it specifically, just observing that it seems to address the right problem - that money is just debt - whereas Bitcoin simply creates a finite resource to be fought over.