Seriously impressive.
Slan,
D. 
I can’t get youtube at work, but is that a link to Danny McCaskill’s Inspired Bicycles?
If it is, then it’s awesome. He’s become a bit of a celebrity up here as a result of it.
Yes, and it’s freaking incredible. The video
mentions “street trials” riding. Am I correct
in inferring there are contests for this sort
of riding?
yep
it’s the urban version of the mountain bike trials
some of each: http://www.youtube.com/results?search_query=mountain+bike+trials&search_type=&aq=f
Amazing! I was not aware of either.
I guess the biggest difference is in
the bike, not necessarily the surface.
some spots in mountains are softer 
I like how the video starts with one of his “failures” and how he is truing his tire afterwords.