I agree with 98% of Sheldon's ideas. One word of caution about sliding back on the seat. I once saw a guy slide back so far that he was actually behind the seat. It was a very dramatic weight shift. Unfortunately, as he was coming to a stop and tried to slide forward on the seat, his slightly baggy shorts got caught on the seat and he went over on his side trying to get his shorts un-hung from the seat. As I watched this I thought that there was also another possibility which is slamming into the back of the seat with one's less protected portions of one's anatomy.