Prisoner's Dilemma

For those of you who didn't see it, at the end of the movie Dark Knight, the Joker set up a real life prisoner's dilemma situation in which two boats had to make a decision. Each boat had a button that if they pushed it before the other boat, they would be saved. Here's a clip from the movie demonstrating it.

http://www.youtube.com/watch?v=TmUWRJInwhk