How Hollywood makes prop money

Prop money looks like real money, with one major difference, one side is blank. That wasn't always the case. The $1 trillion in prop money used in Rush Hour 2 was printed on both sides and it looked so real that people working on the set took bills and spent them in stores, resulting in the Secret Service seizing the money (which cost the prop house $100,000 to make) and burning it.

[Via Dooby Brain]