I was talking to one of the managers at Artichoke Joe's in San Bruno (Calif) who told me that about 50 of their $5,000 plaques were "out" for that reason. He said some find the plaques both more convienient and safer than a big stack of $100 bills. Artichoke Joe's redeems all their chips, no matter how old, by the way. Only exception are the counterfeit ones, of which there are a fair number in circulation, he said.