Historically, household robotics have made for fabulous science fiction but miserable business ventures. Even chronically ingenious entrepreneurs like Atari's Nolan Bushnell and the British innovator James Dyson of vacuum cleaner fame found that their robot ventures did a better job of capturing imaginations than customers. And with the notable exception of Sony's cute but useless Aibo robo-dog, technology's giants have all steered clear of the mass-market robot. No "General Robotics" here.

Yet MIT artificial-intelligence guru Rodney Brooks, cofounder of the Asimov-inspired startup iRobot, seems oddly optimistic about the prospect of robotics. His reason? The technology has finally acquired that vital human ingredient that has made a number of similar industries possible: hobbyists and enthusiasts. "Over 20 years ago, people who liked new technologies played with PCs," says Brooks. "Now they're playing with robots. The first PCs couldn't do very much, and neither can the first generation of robots. But they get people interested and excited."