What about bitcoins? I thought you could convert those back to dollars.
As it turned out the Digi-cash folks had all the patents and were being real dicks about licensing so we never got to test the question.
I can absolutely predict that if you can buy several hundred thousand dollars worth of bitcoins from person X, and then go to persons P, Q, R, ... Z and redeeem them back for cash, that the authorities will shut down that sort of thing quite quickly.
It's already been done:
That's 400k BTC (about $400k) being sent to a number of different accounts.
edit: Ah, I see your point. You said "redeem back to cash". Yes, that probably wouldn't work in an economy only worth a few million :)