As the name suggests, Trilobyte is a bottom feeder. It's round, 15 inches in diameter, and about six inches tall. It's about the size of a stack of LP records. The exterior plastic comes in either a stylized ruby/dark red or turquoise blue. Inside, you'll find the basic vacuum parts, including the sucking hardware and the refuse bag. Also inside are a couple of motors and wheels, which let Trilobyte roam around your house, and a microprocessor with rudimentary programming.

What's your opinion? Post comments, rants, and raves on the Fresh Gear Message Board.Trilobyte works on one room at a time. When you release it, the robot sidles up to a wall, and then slowly maps the room's perimeter. It uses sonar along the leading edge to detect walls, furniture, people, and animals. It also has a physical servo-connection that detects when Trilobyte has bumped into an object.

After defining the room's boundaries, Trilobyte uses a random pattern to roll around the room, sucking dirt as it goes. We tested it in one of our conference rooms by dropping white dots from a three-hole punch machine around the floor. In about 10 minutes, Trilobyte had sucked all of our mistakes right into its maw. It was easy to see why the round shape was a brilliant breakthrough-- Trilobyte can't get caught in corners or other weird angles in your house.

Trilobyte will only work on low-pile rugs, area rugs and wood floors. It's intelligent enough to climb over small creases in the flooring (like where a rug meets a wood floor) but it doesn't work well on shag carpets. It has no concept of stairs. Thus, you can't let it roam at will about your house.

The internal batteries last about an hour, and Eureka recommends you charge up the robot, put it in a room, shut the door, and let it roam about until the battery dies. By then, your room will be clean.