Watch these robotic cubes climb and move around each other, without any EXTERNAL MOVING PARTS. It's truly insane, and a pretty awesome achievement for technology.
The blocks, called M-Blocks, have a flywheel within them that spins at 20,000 revolutions per minute. When the flywheel stops, it "imparts its angular momentum to the cube." On the edges of the blocks and on their faces, are magnets that allow the cubes to attach to each other. Peep the magic above.