One of the most obscure concepts at the show was this Segway all-terrain vehicle. Naturally it boasts electric drive and Segway's signature gyro-stabilized balancing capability, meaning you can pop a wheelie and hold it, even at a stop. The Centaur was revealed by Michelin because it is fitted with a bold new concept in airless tires being pioneered by the company that invented the radial tire. Here's how it works: The tread is bonded to a strong loop of steel or composite material. The vehicle's weight hangs from a series of polymer plastic spokes that connect this loop to the hub. The concept, known as the Tweel, can bear the load of a pneumatic tire four times its size, it can cushion bumps five times as well as a pneumatic tire, and the contact area can be nearly doubled for improved handling. Noise, mass, and rolling resistance have to be improved before the Tweel is ready for high-speed, high-load passenger car applications. Watch for more on this promising technology.