Watched your vidio, it looks great. I would like to see sombody on it (put a helmet on). We don't have the tech people to buld something like yours. I did see one like that at Huston stack attack many years ago that a guy built and his work alot like yours. Our used the fisher price motors and moved at a fast walk and tended to pull to the right a little. but was easy to build. We are currently working on a four wheel drive one that uses four small chip motors and is much faster. Check the bottom of our web page
http://team1322.org/joeway.htm . Note ours is nothing like a segway thats why we call it a Joeway.