I was once stuck on a plane on the taxi-way for over an hour (some doofus hoocked up the push-back truck wrong and it busted the front landing gear, so they had to get if fixed before we could get moving again). I remember that one of the things they did to entertain us was ad-hoc gambling. "Okay, put your name on a dollar bill, put it in this jar. If we pull your bill, you win the money!" Yeehaw.
I believe that was the flight where Robin Williams was on the plane, but that may have been a different flight on that trip.