Building a hand out of Lego bricks is pretty cool, I guess. One that moves using a series of gears and motors? OK, you're getting there. One that's controlled via a separate exoskeletal hand controller? Yes, that qualifies as awesome.
That's just what David Hyman did, creating a controller that you actually put your hand into. When it's snapped onto all of your fingers, you simply move them and the robotic counterpart will mimic your every move. And did I mention already that this is all made out of Legos? It's stuff like this that makes me realize how much of the potential of my toys I wasted when I was a kid by just not being smart enough to use them properly.