There are several things that come to mind when someone mentions Microsoft’s Kinect. “No physical interface” is one. Another popular thought is “Awesome hacks.” This is indeed an awesome hack, but it’s one that proves that “no physical interface” does not have to be true.
Garratt Gallagher won Willow Garage’s Robot Operating System open source contest with this system that enables the user to draw buttons on paper with a Sharpie and then actually USE the buttons to control a sound board. There’s no reason this couldn’t be used as the basis to allow any kind of virtual button control though; it certainly doesn’t have to be limited to just a sound board. I’d love to know what “button purist” gamers have to say about this!