That's essentially what Andy Wilson, one of the designers of Microsoft Surface, has done with his latest project, called LaserTouch.

The idea is to train a camera down on a sheet of infrared laser light and then keep track of what it sees on the surface. Track the lasers on a flat-screen computer monitor, and you've created something that feels remarkably like a touch-screen monitor.

To the uninitiated, Wilson's LaserTouch software seems to work a lot like Surface, Microsoft's tabletop computer that can read reflections on its screen. It responds to gestures, so instead of clicking on a mouse, the user drags and drops with a fingertip. Squeezing two fingers together shrinks the screen, and a quick dragging movement can flip the screen to the next window.

Surface is being rolled out in AT&T stores, where it's being used to power customer-information kiosks.

Because LaserTouch can work with screens that have a much higher resolution than Surface, Wilson said it could be used by office workers, if it's ever brought to market.

Using experimental presentation software developed by Microsoft Corp.'s Office Labs called Plex, Wilson was able to navigate through PowerPoint-like presentation slides on a 30-in. flat-panel display.

The Microsoft researcher demonstrated LaserTouch at a Microsoft Research event held for the media and researchers at the software vendor's campus in Mountain View, Calif.

This was actually LaserTouch's second public outing. Wilson said that his software was also used to power the interactive whiteboard technology called Touch Wall that Microsoft Chairman Bill Gates demonstrated last week at the company's CEO Summit last week in Redmond, Wash.

What has Wilson excited, though, is the fact that LaserTouch could work on virtually any flat display, including a projection screen. The two lasers and a camera used in his demo cost just a few hundred dollars, he said. "By far the most expensive piece is the display."

Wilson's earlier research showed how technology like LaserTouch can mesh with the real world in interesting ways. Wilson showed a demonstration video of two people playing chess against each other in different locations. Each one put a white piece of paper and white or black chess pieces on the board, and the LaserTouch software did the rest, superimposing a chess board and the opponent's pieces onto a projection screen. The only drawback: When you take a piece, your opponent, not you, has to remove it from the board.

Rick Rashid, senior vice president of Microsoft Research, said, "It's fun, but I really think it's the future."