The startup’s technology puts sub-millimeter accuracy at user fingertips, offers control gestures like pinch-to-zoom, and promises new applications that make the Kinect and its kin look like yesterday’s news.

Hands-free motion control, a technology pioneered by Nintendo’s Wii and later improved upon by Microsoft’s Kinect, just took a very big leap forward. Industries from gaming to surgery to architecture, engineering, and design may never be the same.

With the unveiling today of its Leap 3D motion control system, a San Francisco startup calledLeap Motion has, well, leapfrogged the state of the art in this young field, giving users the ability to control what’s on their computers with hundredth of a millimeter accuracy and introducing touch-free gestures like pinch-to-zoom.

Leap, which comprises both a small USB input device and a sophisticated software platform, is expected to cost $70. But while users will have to wait until early next year to get their hands on it, what the company is showing today seems likely to get developers and users in a wide range of industries very, very excited.

By now, most people have seen Kinect in action. The Microsoft system has become a huge success by allowing developers to make games and other software that let people control what’s on their screens with their bodies. That’s great for dancing, fighting, and sports games, plus many others, but Kinect’s ability to recognize motion ends at users’ hands.

Leap, by comparison, can sense motion down to the most subtle movements of a finger, which the company says is 200 times more sensitive than anything else on the market. The system creates a “three-dimensional interaction space” of four cubic feet and is more precise and responsive than a touchscreen or a mouse, and just as reliable as a keyboard.

That means everyone from game designers to surgeons to architects and engineers may soon have a host of revolutionary applications that will soon be coming their way.

In a demonstration to CNET, Leap Motion CTO David Holz showed how the Leap is adept at a range of functions, such as:

• Navigating an operating system or browsing Web pages with the flick of a finger
• Finger-pinching to zoom in on maps
• Letting engineers interact with a 3D model of clay
• Precision drawing in either two- or three-dimensions
• Manipulating complex 3D data visualizations
• Playing games, including those that require very “fast-twitch” control
• Signing digital documents by writing in air