Michael Weber's Four Dollars in Change

This effect is intended to be used as an entertaining magic routine that leaves the spectator in a comfortable position to tip the performer but also allows the spectator not to feel "forced" into tipping the performer if he/she doesn't care to.  Instead, the spectator should be entertainingly fooled by the effect, and any preceeding magic, and should already want to give the performer a tip, this is just a perferct opportunity.