It’s time we admitted to ourselves that most of us don’t really want robots. At least, not robots as they exist now–expensive and almost useless, able only to amble across the room, pretend to be a dog, or pummel another robot in gladiatorial combat.

No, the majority of consumers don’t want or need a fancy wind-up toy. What we want is a robot that can do the stuff we can’t find time for, the stuff we find unpleasant. Those in search of mechanized entertainment can keep their pricey Sony AIBOs and Lego Mindstorms –the rest of us want a cheap robot who will cook for us, bring in the mail, and clean our houses.

If the purpose of a personal robot is to perform tasks we don’t want to handle, it seems odd that so much robot research is being directed toward making them seem human. I don’t like to mow the lawn; a humanoid robot doing it for me would just make me feel guilty. And it turns out the human form isn’t particularly practical for robots, anyway. The Japanese robot SDR-3X is a bipedal machine with a head, arms, and torso. It can toddle around and look vaguely like a person, but what’s the use? It can’t even vacuum the floor.

Enter . . . Roomba.

By now, we all know about the Roomba, first in a line of commercial robots developed by a Massachusetts company called iRobot. Roomba is a mass-marketed personal robot, available for under $250, that scoots around a room, avoiding obstacles, and sucking up debris. Set it, forget it, and come home to sparkling floors–so say the marketing claims.

So far, half a million of them have been sold. While it may not have the flash of the Jetsons’ maid Rosie, the Roomba is the first successful consumer robot.

Of course, some users find Roomba more effective than others, and skimming online forums devoted to the topic reveals that the glitches aren’t entirely worked out. The little, disc-shaped ’bot can get clogged pretty quickly, and it sometimes can’t tell the family pet from a wall. "Sensitive electronics + floor cleaning = hassle, hassle, hassle," laments one user.

"Roomba rocks!" rave others. But love it or hate it, the Roomba is not quite what most of us think of as a real robot . . . yet.

The future looks bright for iRobot, which was founded by two graduates from the MIT Artificial Intelligence Laboratory. They’re also developing government and industrial robots to do unpleasant or dangerous tasks, such as mine-sweeping, hazardous materials sampling, and confined space investigations.

The company got a lot of attention when its sturdy, tracked ’bots were used at the World Trade Center site to search for survivors. Backpack models have been deployed in Afghanistan and Iraq to sniff out explosives and mines. Some of the concept robots on iRobot’s website are a bit scary looking, and their functions seem suited for a fearful world that needs expendable, anthrax-sniffing machines.

Back on the home front, most of us just need a good vacuum cleaner. And although it does not detect poison gas, the latest-model Roomba does sport something called "dirt detection" technology. When particles are being vacuumed up, sound transducers send a signal so Roomba "knows" to stay on that spot until it’s clean.

iRobot’s company name, of course, is a reflection of one of the great literary works about robots. Helen Greiner, chair and cofounder of iRobot, was thrilled by the works of Isaac Asimov when she read his stories in high school. For her robotics company, she wanted a name that would work on different levels. "The name comes from this incredible science fiction source, the guy who brought robots to popular imagination. The ‘i’ in the name can stand for ‘intelligent,’ as well."

As a roboticist, Greiner is a woman in a seemingly male-dominated field, but, she notes, "There are more women roboticists than you might think. Many of them came out of MIT. There was this cluster of women roboticists there working on cooperating robots, on how babies learn, on swarms of robots, on what happens when robots get very small."

The MIT lab "really encouraged people to do their own thing," Greiner says. For her, that was figuring out how to make a cheap, practical robot to sell.

"I was interested in business. I might have been the only one," she laughs. She especially appreciates that the stories in Asimov’s I, Robot are built around the products of a single company, US Robotics and Mechanical Men.

Greiner is a sort of real-life Susan Calvin, the female protagonist of many of Asimov’s robot stories, when she talks about robots. "They can do things with less effort, safer, and in many cases even better than a human could do. . . . Once you get the first practical device on the market, there will be the technology to start developing the next generation. . . . I’m a believer."

While the Roomba still doesn’t have a positronic brain, it does have some sophisticated circuits, and Greiner hopes that each new model of the robotic vacuum cleaner gets a little better at doing its chore. She clearly understands that most of us can’t afford and don’t want another expensive toy.

"It’s not a toy, not a high-tech thing. It’s just a practical thing. We finally got a robot out there that was at consumer prices and got a job done. Think of window washing, toilet cleaning, bathtub scrubbing. We’re not a vacuum company, we’re a robotics company, and all these tasks are opportunities for development."

But even if we only think of our robots as chore-machines, we still want to love them. Roomba owners come to think of their little ’bots as pets, or even something more . . . anthropomorphic. Roombas hum around the room, making self-satisfied noises, then scoot back into their recharging stations when they need a break. They seem at least as smart as a cat.

Helen Greiner has heard from many happy customers whose feelings toward their robot changed after they spent time with it. "People think it’s an appliance when they buy it. But when they get it home, the only thing they’ve seen that works like it is a creature. So they name it and start to feel affection for it."

I wonder if this affection is a side-effect of the Roomba’s small, unobtrusive shape. It’s low enough to get under furniture and it’s round to maximize mobility through tight spaces. For some reason, when it’s moving around, many users find it "cute." It’s almost like having a fast-moving limpet in the house. You can’t imagine it hurting you–although your cat may feel differently about it. On the other hand, some walking robots being developed now look more like big spiders.

Note to the robotics industry: we don’t like big spiders.

Helen Greiner doesn’t share my uneasiness about walking robots, although she isn’t a biped purist. "Legs are great over rough terrain. I enjoy having legs, but there’s a reason I jump on a bicycle or get in a car sometimes."

"I’m a legged robot person by background. I do believe there are a lot of good things about legs, but you’ve got to be practical. We don’t have the strength-to-weight ratio yet. People say robots have to have legs to climb stairs–that’s just not true," she says.

Greiner believes that robots with very sophisticated bodies and brains are on the horizon. "I think we will get there," she says.

But do we want to get there? As such devices become more commonplace, smarter, and more self-motivated, household robots may be our pets, or they may be involuntary laborers.

In fact, setting aside stories of machines running amok, robots have been portrayed as benign, mechanical helpers almost since science fiction began. From Robbie to C-3PO, they are intelligent, friendly, and always willing to do our bidding. Far from representing the terrifying rise of automatons, they function merely as wish-fulfilling servants. The literary and cinematic robots that garner the most adoration and affection are those who do the dirty work without complaint, or with a little charming sass. Would you–could you–make R2-D2 vacuum your rug if he didn’t want to?

Science fiction authors, including the inestimable Asimov, have dealt with the issues of robot exploitation in many ways. Robots reflect our feelings about the mindless production work that seems inherent to capitalism, and at the same time, they play on our fears of being replaced by automated workers.

Human reactions to technology have always been complex, but never more so than when the lines between brains and circuits become blurred. Conflicted emotions about Pinocchio-like androids provide much fodder for science fiction, as in Brian Aldiss’s "Supertoys Last All Summer Long" and the uneven Steven Spielberg film based on it, A.I.

The uneasy relationships between people and their mechanical counterparts were doubtless what inspired Isaac Asimov to come up with the Three Laws of Robotics, which gave robots a moral code in relation to humans. Will we see something like the Three Laws programmed into robots someday? Nope, says Helen Greiner. "Asimov was writing those stories in the forties. The understanding of the difficulty of programming was not there."

"But we’re getting to parts of the Three Laws in other ways," she continues. "The Roomba won’t fall down stairs . . . but does it know it’s keeping itself safe?"

Greiner and other roboticists see robotic "psychology" questions, as well as more practical concerns, as intriguing challenges to tackle. "Working in this field teaches you stuff about being human and how difficult some things we take for granted are."

Things like cooking dinner. Programming a small robot to vacuum a room is one thing, but where on-the-fly decisions about what I eat must be made, give me gray matter any day. It’s possible that there are some chores not suited for robots.

Helen Greiner and iRobot, along with the emerging competitors in this nascent market, are working to find out what robots can do for us. Greiner says American markets, unlike those in the Far East, respond more to practical uses of robots as opposed to entertainment uses. But she is also quick to mention that Roomba has become a favorite of robot tinkerers, because of its low price and varied capabilities.

Roomba’s programmed code is not open source, but robot hobbyists can modify its collision and detection sensor settings, mount things on its chassis, and make it do all kinds of things that will no doubt void the warranty.

When speculating about what people might modify their Roombas to do, Greiner jokingly suggested that someone might program one to bring beers to its owner. Well, there goes the "real-life Susan Calvin" theory. It seems likely that Asimov’s serious heroine would have considered such a task demeaning to her beloved robots.

I ask Greiner if she agrees with Susan Calvin that robots are easier to get along with than humans. "Loaded question!" she deflects with a laugh.

Obviously, robots as they currently exist are as easy–and as hard–to get along with as a car, or a coffee maker. They don’t yet have real personalities, or the ability to respond to human emotional cues or subtle variations in their environments. They are implacable and steadfast doers of chores.

Or are they?

How many science fiction horror films do we need to see to understand we can’t trust robots? No matter how cute and helpful they are, at some point, their "dirt detection" sensors will glow blood-red, and they will leave their charging stations, creep across the bedroom toward our sleeping forms, and exact revenge for all the dog hair they’ve had to swallow.

It could happen.