I've watched tons fo Derrin Brown videos. His experiments are pretty interesting. Subliminal advertising and the chess grandmaster ones were the most interesting.
I agree, the advertising one was pretty cool. But the chess grandmaster thing was just a lame trick. He let all of them play against each other through his memory and beat some random scrub (which was probably planned).
See what happens when you leave a wallet on the ground: http://www.youtube.com/watch?v=bxYCh_p2Mjs