(FORTUNE Magazine) – In theory, the idea has obvious appeal: A robot mower cuts the grass while its owner spends a couple of hours lazing in a hammock.

In practice, however, the Toro iMow, a $900 contraption that resembles a giant, mutant computer mouse with spinning blades, is more Blade Runner than The Jetsons.

The film Blade Runner was based loosely on a Philip K. Dick science fiction novel called Do Androids Dream of Electric Sheep? As the iMow grazed randomly across my lawn, it suddenly dawned on me that Toro--or, more accurately, Friendly Robotics, the Israeli company whose technology Toro has licensed--has dreamed up one of the world's first electric goats.

In two hours the iMow gave our suburban yard a punk haircut. Instead of the lush carpet of green that we had been expecting, we were presented with the horticultural equivalent of a drive-by slashing.

The problem is that the iMow is even lazier than I am when it comes to yardwork; it quits after just a couple of hours a day. As a result it is best confined to small, open spaces, preferably smaller than half a tennis court. Anything larger or more complicated and the results are goatlike, with random, scruffy patches of untrimmed grass.

Although its feeble computer brain calculates true north and tries to be at least vaguely mindful of its location, the iMow is significantly less intelligent than a goat. It grazes until it bumps into something--a tree, perhaps, or a rock or a leg--turns around, and heads off in another direction until, once again, it bumps into something or detects that it has reached the perimeter of its yard. (The first step in setting up the iMow is to lay down a low-voltage perimeter wire to define the cutting areas and to stake the wire into the ground so that the iMow won't accidentally cut it.)

Like a goat, it will attempt to eat foreign objects left lying in the grass, like golf clubs, garden hoses, shoes, toys, and small, stupid pets.

It continues in this fashion until its batteries are exhausted, typically in less than three hours. In our case it had randomly scalped only a portion of the yard before we found it, nearly spent and bleating pathetically; we used the manual controller to walk it back to the nearest power outlet. Toro recommends that it be recharged indoors, ideally in a garage, because leaving the charging batteries out in the rain is a no-no.

The manual controls, which resemble a Nintendo videogame controller, enable the iMow to be guided into areas it cannot--or stubbornly refuses to--reach in automatic mode. But operating the iMow in manual mode is so tedious that the phrase "watching the grass grow" comes to mind.

The bigger problem was that we had company coming the next day, and there wasn't enough time to recharge the iMow's twin 12-volt batteries to permit the iMow to continue its haphazard exploration of the yard. The iMow's manual says it takes 24 hours to recharge the batteries to prepare it for another 2 1/2-hour workday. Our Texas-sized yard, or at least the portion of it contained within the 500 feet of perimeter wire that comes with the iMow, appeared to offer the robot mower steady employment for a week.

To its credit, the iMow did prove itself to be a mostly quiet, nonpolluting mower that creeps around the yard mostly unattended, while nibbling grass to one of six specified heights. Where it did cut the grass, it mulched the leavings exquisitely.

Our greatest fear, or perhaps secret wish--that the iMow would run amok and eat the neighbor's yapping little dog--went unrealized. Nor did the iMow vandalize any shrubs or flower beds. It was not "whisper quiet," as promised, but neither was it noisy enough to disturb the neighbors.

Who should buy the robot mower? Hopelessly addicted gadget lovers, of course, especially lazy ones. Other candidates include people who have severe allergies or physical disabilities that don't permit using self-propelled lawn mowers. Who should not buy one? People with sloping yards (anything steeper than 15 degrees stops the iMow in its tracks) or yards with lots of trees.

The iMow's main challenger--at least among affluent, indolent gear-heads--is the Husqvarna Auto Mower, a $2,000 device that appears to work harder and think smarter than the iMow. The Husky weighs less than 20 pounds and automatically returns to its recharging dock when its batteries run low. In theory, one could set up the Auto Mower, go on a two-week vacation, and come home to a manicured yard. It even works in the rain. Husqvarna plans to sell a solar-powered version of the Auto Mower in the U.S. next spring.

Elsewhere on the robot housework front, Friendly Robotics is reportedly working on a sonar-equipped robot vacuum cleaner, as is Eureka, a division of ElectroLux. Can a robotic snow blower be far behind?

What does one do with all the free time created by the electric goat? Friendly Robotics is developing a "Mary had a little lamb" robot caddy that will follow its owner around the golf course while toting a set of clubs.