Against all odds, GM and Segway let us inside their precious P.U.M.A. prototype , and we went for a quick jaunt down 18th St. We couldn't drive it, unfortunately, but there was plenty of action to be had from the passenger side. Starting from a rest on four wheels -- the main powered wheels and the front two "safety" wheels; we never touched the back two to the ground -- the contraption shoves itself up onto two wheels quite gracefully, with the passenger compartment moving slightly independently from the wheelbase and floor. It was a bit odd, but not at all unpleasant, and we were soon zipping down the road. Since the P.U.M.A. is self-balancing, we felt way less force when accelerating and decelerating than we would in a car, since our body was being "leaned" into it instead of pulled along. Turning on a dime is quite fun as well, and we could see this thing making itself quite at home on city streets. While it remains to be seen if GM and Segway can commercialize this in time, and for the right price, we're fairly enamored -- at least it's something different, and it's already twice as interesting as Segway ever managed to be.Camera work and moral support courtesy of Autoblog Green's Sebastian Blanco