After seeing the balancing skateboard, we thought we would built a Balancing Platform to test out the technology. We bought some rear ends of kids scooter for the drive wheel/motor and the electronics that XenonJohn suggested.http://www.instructables.com/id/Easy-build-self-balancing-skateboardrobotsegway-/
Making a stand-on balancing unit is the same as a skateboard but the wheels are wider apart and the board is turned 90deg so the rear end of kids scooters were used. They were quite small but were quick and easy for testing.
Just don't hit any big bumps! We only had a few bit of skin missing from our shins and one hole in the wall!