Touchscreens normally involve, well, a screen, but the one Ubi came up with has no physical form at all.
Granted, that isn't quite true. There are some physical components, they just aren't screen components per se.
made a system composed of a projector and a Kinect sensor.
The projector creates the image on a surface and the motion sensor tracks body movements and interprets them as taps and swipes would be interpreted by a normal display.
Interesting to note is that the system is part of Microsoft's Kinect Accelerator program and has impressed the company enough that there already are plans for sending models to offices, hospital and other venues in need of public displays.
The price of one implementation should be quite a bit below that of a TV-sized touchscreen, so we don't mind betting on Ubi's success.