For those who think the Segway isn't small enough, Honda might just have your device.

It's called the U3-X and most people think it looks like a space-age unicycle. And it's actually fairly striking in its ability to move not just forward and backwards but sideways and diagonally, too.

Top speed is 3.7 mph, which for most people would be a power walking pace. The device moves in whatever direction its user leans towards.

Honda provides some more information about the device in a press release. An excerpt:

This new personal mobility device makes it possible to adjust speed and move, turn and stop in all directions when the rider leans the upper body to shift body weight. This was achieved through application of advanced technologies including Honda's balance control technology, which was developed through the robotics research of ASIMO, Honda's bipedal humanoid robot, and the world's first* omni-directional driving wheel system (Honda Omni Traction Drive System, or HOT Drive System), which enables movement in all directions, including not only forward and backward, but also directly to the right and left and diagonally. In addition, this compact size and one-wheel-drive personal mobility device was designed to be friendly to the user and people around it by making it easier for the rider to reach the ground from the footrest and placing the rider on roughly the same eye level as other people or pedestrians.

Honda is planning to showcase the U3-X at the 41st Tokyo Motor Show 2009 (sponsored by JAMA) which will begin on October 24, 2009 at Makuhari Messe in Chiba, Japan.

Striving to propose the next-generation mobility which expands the joy and fun of mobility, Honda has been conducting robotics research since 1986, including ASIMO, walking assist devices and U3-X, at the Honda R&D Co., Ltd. Fundamental Technology Research Center in Wako, Saitama, Japan.

The device is still a concept so it isn't being mass produced yet. One serious drawback is that its lithium battery lasts for only an hour.

At that rate, a lot of people would wind up walking back home with their powerless U3-X's under their arms.

Also, it doesn't look like the most comfortable ride. Because a rider signals the direction she wants to go in by leaning in that direction, it looks like she has to sit fairly still or risk sending the device off into the wrong direction.