uTouch is a project from the researchers at the University of Washington. They want to create touchscreens by mapping your house's unique electromagnetic interference signature. Here's how they explain it:

Basically, the electricity running through the wires in your house has a unique electromagnetic signature. There is the “carrier wave,” provided by the power company and your nearby substation, and then every single kink and switch along the way modulates the EM signature until it is quite unique. What most people don’t realize, though, is that every device that is plugged into a wall outlet also changes your EM signature. Your TV doesn’t just suck power from your house — it’s a two-way street, with the electronic components in the TV producing interference that change your house’s EM signature.
The project's electromagnetic signature sensor can be detected by infrared or spectroscopy, or in other words, any electronic item plugged into your house's electrical system can serve as a touchscreen.

There are no plans to commercialize uTouch yet, but apparently the whole system uses off-the-shelf parts, so it should be cheap and easy. Check out the video below:

[Technology Review]