The odds of pulling that one off can only be slightly improved if you're a touring Mongolian circus performer. I still don't know how he did it.
Now, look through some of the other videos to see examples of those who were, er, less successful. I especially like the one where a guy is teaching his buddy to ride a shiny red SV650. The student clearly has never been on a motorcycle and, in a panic, confuses the controls and cracks the throttle wide open, going from like 5 mph to about a zillion. He jumps the curb onto a nice grassy area and runs smack dab into the ONLY tree within sight. The funniest part is the audio: the teacher (and most likely the SV's owner) just repeating "Oh sh*t, oh sh*t...oh, *****!" I've watched it a million times and still laugh.
Lots of other cool stuff on there, including many squids doing squidly things and paying with pounds of flesh, other racing accidents, silly stunts gone wrong, and some great euro TV commercials. Most of the stuff is motorcycle related, but not all. Enjoy.