DVD decks, satellite dishes, wide-screen TV--you or someone you know has bought every conceivable techno-widget, and at least can take solace that no new category of mega-product is about to come along, right? Cancel that solace. According to Rodney Brooks, director of the Artificial Intelligence Laboratory at the Massachusetts Institute of Technology, the next big consumer item is going to be robots--for the home. Robots that dust, do laundry, straighten the towels. He thinks they will be practical within 20 years or less. You will issue some command such as, "Get the newspaper." Your robot will faithfully clank out the door, pick up the paper and bring it to you, shutting the door of course.

That household robots are just around the country is one of many wild notions advanced in Brooks's new book Flesh and Machines: How Robots Will Change Us. Flesh and Machines is a fascinating look at how top researchers - its author is one - have tackled such challenges as teaching prototype robots how to walk around obstacles or recognize faces, acts that come automatically to people but are daunting trials to devices. This compelling, cleanly written book is not techno-cheerleading; the author admits there are all kinds of drawbacks to robots and intelligence-emulating computers, including the most obvious, "Why would anyone need or want this stuff?"

But Brooks thinks robots are coming, ready or not. And so, he thinks, we'd better start thinking through what we would want robots to be like, what their programming should permit and what it should forbid. And we'd better, he thinks, start contemplating the day when "one of our robots earnestly informs us that it is conscious, and just like I take your word for you being conscious, we will have to accept its word for it."

First things first for a moment, because at present no one at the Artificial Intelligence Laboratory of MIT has the foggiest notion of how to make a robot conscious. The lab's current projects, with names like Cog and Kismet, are metallic creatures roughly the size and shape of large dogs (see pictures). Some of the lab's robots travel on wheels or lunar-lander style legs, and have dual video cameras (for stereo vision) atop crane-type necks that swivel around.

Brooks and his grad students have taught their robots how to maneuver around rooms without crashing into tables or people, how to pick things up and move them, how to recognize faces and voices. That's about it at the moment - they are not, so far as is known, plotting world domination.

Some functional robots already exist, although of course nothing like the nervous C3PO of Star Wars or the benevolent Robbie in Forbidden Planet. Factories use manufacturing robots, mainly for welding. They are very sophisticated in the ability to perform precise welds, but simpletons in the sense that this is the only task they can do.

Three years ago, Sony got considerable press for offering a $2,500 robotic dog named Aibo that could walk, fetch balls and exhibit simple moods. Why you'd want Aibo for $2,500 when you could get a real dog for considerably less is a question the market answered: after an initial flurry of impulse purchases by dot-com babies, Aibo started languishing on stores shelves, and is no longer sold. The weird thing, Brooks points out, is that Aibo owners swore these robot dogs knew their faces and preferred them over other people. Sony did not put face-recognition into Aibo chips! Still, observing that people respond positively to the fact that dogs watch them as they move about the room, Brooks has programmed Cog to do the same. People who meet Cog don't think it's creepy. They think it means the robot likes them.

And you can already buy rudimentary robots that vacuum or mow. Discovery Channel sells a vacuuming robot for $825, advertising that you can leave it on and come home to a freshly vacuumed house. You'd leave the house with an autonomous vacuuming machine turned on? Who knows how many lamps you would find knocked over and smashed, though presumably the pieces would be efficiently vacuumed up. Brooks himself bought a mowing robot, and experienced nothing but frustration trying to make the thing work. Brooks had to install complex radio guide gizmos around his lawn. Then the robot would wander at all angles, mowing zigzags but leaving tufts, till its batteries ran down and it sat plaintively beeping in distress for someone to come along and plug it in to recharge.

Yet silly as the early robots seem, don't forget that when the first gasoline-powered cars began clunkling and wheezing down streets in the 1890s, detractors would stand at the curb yelling 'Get a horse!'" Automobiles, cell phones, aircraft - these and many other products initially seemed worthless, or good only for very expensive specialty applications. Brooks notes that when he was a boy, lasers were so expensive and impractical they were found only in laboratories. Today most schoolchildren own a laser: they're the key gizmo in a CD player.