I'm no expert in Motocross, but I'm pretty sure you're supposed to stay on the bike.  Chad Reed decided not to do that and the video is awesome. 

 

I've been to some Motocross events at Baja Acres but I've never seen a wipe out like this.  I know motocross isn't a household thing, but it seems pretty sweet.  One of the races I went to had both little kids and a 55 and over division.  Watching both were hilarious.