A circus guy told me years ago about the standard giraffe unicycle, the seat of which is six feet off the ground. I asked him how anyone could get on such a thing, and he simply replied that it was called “mounting.” Yeah, okay. Here’s a video explaining and demonstrating that. And, of course, clowns juggle while riding these things!
http://www.youtube.com/watch?v=3tFDfYoQqAU