Hand gestures are new wave in gadgets

To take these relatively simple applications further, GestureTek and 3DV are looking at adding a third dimension: depth. A regular camera produces a two-dimensional picture. Two cameras together can sense how far away an object is, just like two eyes enable humans to perceive depth.

"We think the interactivity of all this stuff improves with depth," said MacDougall. "You can use that in very novel ways compared to 2-D."

MacDougall demonstrated a prototype of the Airpoint, a foot-long bar with an upward-facing camera at either end. When MacDougall held his finger above it, it sensed the finger's angle and position, letting him control a cursor on the computer screen by pointing.

"We see it initially as a gimmicky business-presentation type device, but you could see it built into the corners of a laptop," MacDougall said. That approach would compete with touchscreen, but the Airpoint has something extra going for it: no fingerprints on the screen.

Reactrix Inc. makes commercial displays that you may have seen in movie-theater lobbies: an image projected on the floor that reacts to people walking on it. For instance, one of its Sprint ads let passers-by kick a football.

At the show, Reactrix demonstrated a depth-sensing system consisting of a display with a sensor and camera array above it. The system can sense and react to people up to 15 feet away waving at or pointing to objects on the screen. It will be on the market for commercial clients this summer.

3DV has another and quite exotic way of sensing depth, that works with a single camera. The lens is surrounded by a ring of diodes emitting pulses of invisible infrared light, up to 60 per second. The light bounces off whoever is standing in front of the camera, and the camera measures when it comes back. Light reflected by closer objects returns faster.

"When light hits your nose, it gets back quicker than the light that hits your cheek," said 3DV spokesman Rich Flier.

3DV plans to make its camera available to consumers by the end of the year, for less than $200, but it's lacking a big-name manufacturer to build it into screens or bundle it with game consoles.

"We want people to play with the camera and develop applications," Flier said. "We hope to see licensees pick it up."

MORE FROM CES 2008

CES 2008 Section Front

CES shrinks, but organizers are pleased At CES, progress comes a step at a time   Celebrity voices personalize driving experience Intel unveils new generation of netbooks at CES   Look ma, no hands! New toy reads your mind Auto tech takes a big bite from Apple Stevie Wonder: Touch-screens alienate blind AT&T exec says he's open to free TV on phones RealNetworks confident of lawsuit win Tiny handheld PC first with organic LED screen CES 2008 Section Front   Add CES 2008 headlines to your news reader: