A Japanese erotic game developer just put two and two together to make what could be the first instance of head tracking combined with upskirts in human history.
The game Tech48 uses a webcam to detect where, in relative space, your head is. Move left and right and the polygonal maiden tracks her head left and right; move up and down, and you get to see her panties.
It's nothing you couldn't do with a flick of your mouse, but it is quite novel. And, you now have both hands free to enjoy this erotic game. (Eating a sandwich simultaneously, maybe?) I commend you once again, Japanese people. [Tech48 via Asiajin via Kotaku]