I have to try this out! Apparently all you need is an Arduino, a few resistors, some aluminum foil, and you can build a simple 3D interface. I really hope this works as well as it appears in the video.
The basic goal here was to make a 3D position sensing system that most people can build, while still preserving some semblance of functionality. To get an idea of possible applications, check out the demo video. If you think you can build one that is simpler and equally accurate, or slightly more complex and more accurate, share in the comments!
Learn more about DIY 3D Interface: Tic Tac Toe