This is so cool (via Gawker and Justin Wolfers): A British gameshow called "Golden Balls" invites contestants to play a version of the Prisoner's Dilemma, wherein the two contestants have to decide whether they're going to "split" or "steal" a pot of money.

If they both opt to split, they split the money. If one opts to split, and one opts to steal, the one who steals it gets the whole pot. And if they both opt to steal it, then neither get the money.

You have to watch this video to appreciate the raw game theory power move that one contestant pulled.