Create your own funny money. Kids earn their own funny money and "cash in" for prizes. (No need for students to put their names on their dollar bills:-) If I go back into teaching, I want to try out this website!
As a kid I loved playing with fake money and well the real one but my parents weren't all that keen on that. I was running my own pretend store, was buying up properties in Monopoly and just enjoying having a few piles of money at hand.