While Microsoft's Kinect brought the idea of 3D motion tracking to the masses, the 3D camera's low, 640x480 resolution, moderate input lag, and bulky form factor have somewhat limited its practical uses. Now, a startup called Leap Motion wants to revolutionize the motion-tracking space with a chewing-gum-pack-sized 3D tracker that promises sub-millimeter accuracy.

Leap Motion claims its small sensor creates a "three-dimensional interaction space" of four cubic meters that can track the 3D position and orientation of individual fingers and even thin objects like pencils in real time, all to a tolerance of one-hundredth of a millimeter. The company says the breakthrough in resolution comes not from the hardware, which consists of relatively standard parts, but from what CTO David Holz calls "a number of major algorithmic and mathematical problems that had not been solved or were considered unsolvable."

A demonstration video shows the technology being used in everything from a first-person shooter to pinch-and-zoom navigation of 3D spaces to mid-air stylus writing in an area smaller than a square centimeter. Writers from CNET and The Financial Times came away impressed by hands-on demos as Leap Motion emerged from its stealth phase.

The San Francisco-based company, backed by $14.5 million in venture capital, has just started taking preorders for the $69.99 PC- and Mac-compatible device, which it plans to ship in December. It's unclear exactly what apps the system will support at that time, but the company told CNET it has plans to offer up 15,000 to 20,000 free development kits to kick-start the software market on its open platform.