Segway, known as "It" or "Ginger" and announced officially on December 2, 2001, is a a two-wheeled platform scooter of sorts invented by Dean Kamen. The base is fitted with two tubeless tires meant to be used for either indoor or outdoor use. The unit operates by sensing minute balance shifts by the rider; leaning forward causes Segway to move forward, leaning backwards goes in reverse, and standing upright stops. It is supposed to be damn near impossible to fall over while riding.

The device has some massively redundant components, having two sisterboards that can each control solo should the other fail, and two motors with the same capability. Five gyros all sense balance and control the motors accordingly. The whole affair is tested to hold about 325 lbs, but the chassis can withstand 7 tons of force.

It is designed to take over for cars and public transport for short trips, such as to the grocery store. It doesn't use gas; it is powered by internal batteries, and it can supposedly run for an entire day on a nickel's worth of electricity. While it may sound an appealing alternative for daily routines, the $3000 price tag will most likely keep it out of reach of the average Joe.

From http://www.time.com/time/business/article/0,8599,186660,00.html