This robot has been developed by Japanese researchers to take advantage of ‘ground effects’, which allows the craft to hover off the ground at an extremely low height, thereby avoiding friction.
The idea behind a craft is that it will someday be used as a train replacement. The lack of friction means it’s able to travel as fast (possibly faster) than a train (which rubs against a rail and wears it down), and in theory, would be cheaper and more efficient than a maglev train, which has a significant drag coefficient.
On the downside, this thing controls like a plane, with pitch, roll and yaw having to be taken into consideration. One concept has the craft in a tightly fitted corridor, which prevents it from racing out of control. [IEEE via PopSci]