Aleksander Polutnik from Slovenien has build this unicycle that works in the same way as a Segway.

1000 watt eniCycle with gyroscope stabilization

eniCycle

Electronic gyroscope measures vertical angle of the eniCycle. 

A complete control runs 100 times per second and stabilizes eniCycle in a perfect vertical position. Because of this eniCycle fits into the category of self balancing vehicles. The speed of eniCycle is controlled by leaning forwards/backwards.

An electric 1000 watt hub motor sets your ride in motion by leaning forwards.

Direction steering is very similar to steering a conventional bicycle. You steer a bicycle by turning the handlebar with your hands. By eniCycle you steer with your feet. This is the reason why learning to ride eniCycle is so simple. You must just learn to use your reflex response on your feet. The average user can learn this in less than 30 minutes.

More info: EniCycle.com