I love this kinda stuff. I wish I had more time to mountain bike myself. Not necessarily like THIS, but in general. Fun way to stay in shape and great scenery.
Alexi
[EDIT] - Shoulda watched the video. It's actually a trials mountain bike (no gears, low seat so you can use your legs as shock absorbers, really sturdy rims and tires and whatnot). Still amazing, and something I'd love to learn to do, but I don't have the time. I don't have enough time to ride down a trail every week let alone perfect my hopping and tailwhip abilities . . . .