Its amazing isn't it? I saw a guy do that at a train station. Niftily wheel himself backwards onto a step on the escalator and hang on with both hands. I've just finished a course in adapted physical education and sports for children with special needs. We had to watch these clips of the Paralympics and some other sports. One of the wheelchair sports our prof showed us was Murderball, which is pretty much, rugby on wheels. The guys who played the game totally blew all our minds away. And the Boccia athletes in the Paralympics had some really deadly accurate shots. Its just...amazing.