So, I've had my latest toy delivered and it's called the Leap Motion.
What is the Leap? In the words of the manufacturer "With a wave of a hand or lift of a finger, you’re about to use your computer in a whole new way. The Leap Motion Controller senses how you move your hands the way you naturally move them. So you can point, wave, reach, and grab. Even pick something up and put it down. Just like in real life. It’s an amazing device for the things you do every day and for things you never thought you could do."
Basically, think of the film "Minority Report" where Tom Cruise interacts with a large screen by gesturing in front of it. That's kind of the gist of the device.