Segments

The Challenge: get the dime out from it's prison without touching the glass or the coins, AND without touching anything with another object.

Note: I like to add the extra red herring of saying they can use "anything on the table" to make it work. That way, they'll spend more time focusing on random objects, and less time thinking outside the box.

The Payoff: using your fingernail, scratch at the cloth in front of the coin, and the dime will slowly "walk" its way out of the glass! It looks like it's moving all on its own, and is a very satisfying payoff the wager.