The Segway PT is a two-wheeled, self-balancing electric vehicle. Users lean forward to go forward, lean back to go backward, and turn by using a "Lean Steer" handlebar, leaning it left or right. You can read more about the vehicle from wikipedia.
A short video showing users using the vehicle in Sentosa.
This is my last posting for the series on Sentosa. The next time I visit Sentosa, hopefully I could take photos of the Universal Studio which should be open by then.