Boggs is an artist who for many years has been making drawings of money and then using those drawings to pay for goods and services. He has been arrested and prosecuted (in the UK) for counterfeiting but was found not guilty.
He has four rules about his money art.
1. He will not sell his unspent drawings of currency
2. He will only spend his drawings of currency at face value (getting a receipt and change).
3. He will not tell anyone where he has spent a drawing for 24 hours.
4. He will sell the receipt and change from the transaction.
So what he does, is spend the drawing. Waits 24 hours. Then sells the changes and receipt to a collector. The onus is on the collector to track down and negotiate a price with the person who got the drawing in the original transaction.
Here's a video of Boggs in action.
I think Boggs is brilliant/