The artist I mentioned in class is J.S.G. Boggs. He draws, or finishes drawing, his currency in public places, waits for a crowd to gather and someone to say something along the lines of 'gee, that's quite a drawing you have there' before asking if they will accept it for the equal amount of goods. His work is one-sided and usually only of low denominations - the stated idea of the performance being to see whether or not someone will accept art instead of money.
What keeps this from being a case of art-for-goods exchange like the picasso's napkin anecdote, is that Bogg's dollars having a subversive ambivalence about them: as hand-drawn copies of mechanically produced objects, they have an aura in the Benjaminian sense. However, because they are reproduced by hand, and not a machine in the mint, they lack the aura of economic value surrounding real currency. When Boggs sells the receipt and goods purchased with his dollar to collectors for a sum of cash much greater than their 'actual' value it further complicates the performance - it is as thought the aura has spread. By making his currency his art, Boggs frustrates the system of art dealers and museums dedicated to translating art into currency, while, through that frustration, building the myth of boggs and increasing the cash-value of his art. The other fun note and testament to this subversive ambivalence is the long list of arrests and acquittals for forgery.