http://www.youtube.com/watch?v=LQOVR2TU7OcThis is part 2 of a 3 part video series about a Rube-Goldberg Machine. My personal favorite and truly amazing.
Anyway I posted part 2 because I'd like if someone could possibly explain what you think is happening around 8:00-9:00. I asked a lot of people now and nobody yet has a good answer.