Riding Honda's U3-X personal mobility prototype is easy. Very easy. Gut-fatteningly, motivation-drainingly, muscle-atrophyingly easy.
The U3-X is a continuation of Honda's unofficial human meat puppetry project, which started in 2008 with a set of assistive robo-legs, and will end with, well, Wall-E. Conceptually, it sits somewhere between two other historically dignified modes of transportation, the unicycle and the Segway. It supports the rider's weight with an omnidirectional wheel, which is actually made of smaller, perpendicularly aligned wheels, and which responds to slight movements in the rider's upper body; a shift of the shoulder in any direction eases the rider across the floor, in a surprisingly predictable and controllable way. It doesn't feel like rolling so much as it feels like floating.
Some other riders hammed it up and fell, but to have anything worse than an awkward dismount, you almost have to try - your feet are never more than a few inches from the ground, and this thing doesn't move any faster than your average person walks. The only thing that takes some practice is turning, since you can't rotate without dragging a toe. It's like controlling an FPS character with only your WASD keys.
Of course, no one wants to end up a meat puppet. But for now, while we still have our legs to fall back on, time spent sitting on the U3-X is a joy. And sitting is really what you're doing - with your feet so close to the ground and your butt planted firmly on the seat, you're basically just sitting in the world's most high-tech rolly-chair. On a Segway, you always feel like you're supposed to be doing something. On the U3-X, it seems perfectly normal just to hang out, and it's frighteningly easy to forget you're sitting on an experimental gyroscopic personal mobility device altogether.
You can't buy a U3-X, and you probably wouldn't want to: the battery lasts an hour, the charm of the loud electric motors would wear off quickly, and the clearance between the wheel and its guard is small enough that it could scrap on uneven terrain. But the fact that this works - and well - is pretty stunning, and the shortcomings don't require much creativity, just time. Since a person on a U3-X doesn't take up any more space than a person on foot, the everyone-needs-a-gyroscope future laid out by the Segway seems, for the first time, not ridiculous.