A 10-spot is always worth at least ten dollars, but some rare 10-dollar bills can be worth a fortune (or at least as much as a small house). Learning to spot the most valuable 10-dollar bills ...

Artist Dan Tague has found hidden messages encrypted in U.S. dollar bills. He would fold a dollar bill as many as 100 times to come up with phrases made up by the letters on the money. Tague's ...