If you really want to see some clerk stumble, use a 2 dollar bill, a .50 cent piece or one of the presidential/Sacajawea dollars.
Add a few Canadian coins in the mixture too. I hate getting them in change and if I spot it, I ask for American currency.
Oh hell no. Then they will be claiming it's all foreign money.
Actually, on second thought, they probably will think those are foreign anyway.
