Nintendo's Wii gave Microsoft its initial inspiration to give the Xbox motion control capabilities that ultimately became the Kinect system.

That's according to a brief history of the project that Craig Mundie, chief research and strategy officer, told at the company's financial analyst meeting this morning.

Mundie said the project drawing heavily on advanced research began about four years ago, when Microsoft was battling with Sony for the hearts of hard-core gamers. Nintendo's Wii showed that there was "another demographic and a different class of applications" for gaming, he said.

"It certainly showed that there was a market expansion opportunity in the gaming business if we were able to do something completely different," he said.

Rather than imitate the Wii, Microsoft decided to take it further and develop a controller-free system. At first it seemed impossible, but "we went from impossible to shipping in about three years," he said.

The Kinect, which goes on sale this fall for $149, also offers a glimpse of tomorrow's computer interfaces, Mundie said:

"It does portend a revolution in the way people will interact with computers."

Following Mundie's presentation, the 180 or so Wall Street analysts were given a chance to try Kinect in a "technology showcase" that's part of the event.