That was what I was thinking before I clicked on the thread so I knew it was a Fool's story. Although with the crazy things that seem to happen now, it would almost be believeable on any other day. It was a pretty good one.
In Investment Biker, the author found that in Western China, merchants wouldn't sell him gasoline for Chinese Yuan. They wanted American Dollars instead in spite of the fact that it was allegedly illegal to use US currency.
Of course this was in the '90s....
When I was younger and you could still safely travel through Juarez, Nuevo Laredo, and Matamoros, I found that it was pointless to convert my US currency to Pesos. The vendors wanted Dollars.
But I'm serious about Pizza Patron. They take Pesos. It caused a bit of controversy. I figure that if they want to take useless Mexiccan paper for their product, let them.