Forget teleconferencing with a screen and a phone. Go for virtual embodiment instead. Send your roving robot to do your talking for you.

Props, or Personal Roving Presences, are the brainchildren of computer scientists John Canny and Eric Paulos at the University of California, Berkeley. The prototype is little more than a hat stand on a rollerskate: a four-wheeled base with a video camera, a tiny screen and a microphone on a thin pole.But anyone with a computer and an Internet connection could use it to attend meetings or meet friends - from anywhere in the world.

Canny speculated in the New Scientist that low-cost personal robots could make standard teleconferences obsolete and cut business travel costs. The idea grew out of an experiment with "floating eyeballs": helium-filled balloons with video cameras and speakers that were meant to act as wandering observing stations. But the floating eyeball tended to drift out of control.

"We found the most interesting thing you could do with it was talk to people," he said. "Then we realized you could be remotely immersed in an environment. The carts were a natural step."

The robot can be turned or moved forward or backward by remote radio control. The theory is that it could amble down corridors, taking advantage of chance meetings or joining in chats around the coffee machine. Canny used it to look around his Berkeley lab and talk to his students while he was away.

The next step might be to give it an arm so that it can gesture. It has an onboard computer and can turn its "head" in any direction. The parts cost just over $2,000, but the price could drop with mass production.

Prop weighs 20 pound - a human could stop it with a hand - so even in the hands of a vandal or a drunk it could not do much harm.