At last, I have found a robot that actually works as advertised and doesn't cost a fortune to own. It's the Roomba automatic vacuum cleaner made by iRobot, a company founded, appropriately enough, by MIT grads.

It doesn't look like a vacuum cleaner at all, but instead like an overweight frisbee or a bathroom scale. You turn it on, choose the size of the room - small, medium or large - and away it goes. It doesn't clean in straight lines, but in a spiral motion, spinning as it moves along the room. At first glance, it looks like it's just pushing dirt away (like those big street sweepers do in Manhattan), but it eventually does pick up every last crumb.

It's hard to picture - you really need to see it for yourself to believe it. Think of those automatic swimming pool cleaners - it's a similar concept, without the wires, of course. You do need wires, though, to charge the battery. It can run about an hour to 1.5 hours on a single charge - about enough to do three medium size rooms.

Another nice feature is the "virtual wall," which is a small gadget that's about the size of an office scotch-tape dispenser. By placing it in an open space, and pointing it at a wall, it forms an invisible barrier the Roomba can't cross. The dust pan is small, so you will want to empty it between rooms.

My wife, Roopa, who's a skeptic about all tech hype, was pleased with the tests at our home. She said she doesn't think it could be our main vacuum cleaner, but would be really useful before a party - something that could clean on its own while you do other chores.

As surprising as it is that it actually works, the price may be the most surprising aspect of it. It's clearly is meant to be a mass market product (unlike those $900 robot dogs). It costs $200, and is sold at stores such as Brookstone, Hammacher Schlemmer and Sharper Image in addition to the Roombavac.com.

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