Dirty Dancing

Roomba the Robot Is Part Vacuum, Part Floor Show

I like gadgets. Right now my backpack holds an iPod, a Palm personal digital assistant and a cell phone that takes pictures and belts out the beginning of Ozzy Osbourne's immortal "Crazy Train" when anybody calls.

All of these possessions strike me as unassailably cool. But the latest addition to my tech-toy lineup -- a robotic vacuum cleaner that looks like a fat Frisbee and occasionally gets lost under the bed -- may have taken me straight from cutting edge to goofy.

That's because there's something both nifty and absurd about my new household helper, called a Roomba. About 13 inches wide, this look-Ma-no-hands vacuum has a big plastic button on its front that makes the device change directions whenever it encounters an obstacle. It bumbles along walls, under chairs and around bookcases looking for dust and dirt. In the middle of a room, or wherever it senses a promising patch of debris, it orbits a spot in the floor in ever-widening concentric circles.

A robotic vacuum cleaner seems like the stuff of late-night TV infomercials -- a cheesy gimmick that would soon end up gathering dust in the garage. But Roomba, available in techy Sharper Image stores as well as housewares big-box Bed Bath & Beyond, is a surprisingly smart little guy: Try to send it clattering down the stairs and it backs away. When it's getting low on juice, it heads back to a home-base power dock for recharging.

Roomba's creator, a company called iRobot Corp., was spun off from research conducted at the Massachusetts Institute of Technology into commercial applications for robotics. The company's other product line is a remote control robot used by police bomb squads and the military to scout for explosives, chemical weapons and land mines. This year's version of the Roomba is the slightly tweaked second generation of a product line that debuted in 2002 and has sold, according to iRobot, more than half a million units.

Roomba and its peripheral gadgets don't require an affinity for electronics to operate, which is good, because anyone who wants an automated vacuum cleaner to sweep the floors is, very likely, too lazy to read a complicated manual.

In any case, I was. So after taking the thing out of its box, I snapped a battery in, hit the power button and punched the button marked clean. With a few electronic chirps, it was off, shuffling around my apartment's hardwood floor with a tinny, grindy noise. After a while of watching it go, I picked it up and pushed another button on the back, releasing a back-end hatch that, bagless, collects whatever debris Roomba picks up. Dust ball city.

For a robot, Roomba is relatively low maintenance. When it hits the corner of a rug it chokes sometimes and seems to pass out. And I have been less than pleased when it chews the fringe of those rugs; fringe gets wrapped around the brush cylinders, and the machine staggers around in drunken confusion. But it was relatively easy to figure out how to pop the brushes out to clean them and send the gadget on its mission again.

After a couple of weeks of living with Roomba, I still have no idea how its electronic brain works. One minute, it will head purposefully down the hall toward the living room. The next, it's veering back to my feet, as if it had forgotten to tell me something. Sort of like a pet with a purpose.

So it pains me to say there's room for improvement: The little fellow is not slim enough to slip into tight nooks and crannies, though a tiny helper brush on its front end extends its reach into corners. And while any vacuum cleaner could choke on a sock left on the floor, I wish Roomba were smart enough to work around it or push it away.

Also, its three-inch height means Roomba can zip under beds and tables where other vacuum cleaners can't, but that presents an occasional problem: At a friend's apartment, Roomba launched straight under the home entertainment center and knocked out the TV's TiVo and cable connection. It also freaked out her dog.

Eventually I found that it didn't pay to try to psychically micromanage Roomba on its rounds. If it missed some debris on the first pass, the battery charge, good for a couple of hours, would send it back again and again over the same spot: Robots don't get bored.

This vacuum is probably not for folks who want the job done quickly. Where technology is usually geared toward taking care of our mundane tasks with speed and efficiency, that's not Roomba's thing. Roomba gets dirty floors and rugs clean, but on its own schedule.

Roomba comes in four models, priced from $149.99 to $269.99. Lower-end models leave out the self-charging home base, take longer to recharge and come with only one "virtual wall," a supplemental device that can be used to keep Roomba in or out of certain floor areas. The $249.99 Discovery model I tried comes with two virtual wall units, and, for those who really want to feel ridiculous, a remote control.

IRobot sells Roomba directly at its Web site, www.irobot.com.