I wanted to comment on the 'First Robotic Vacuum Cleaner' article, but being only an observer, I cannot.
The Trilobite seems to be very different from the Roomba. It makes sense that it looks similar - we all know the navigational advantages of a circular robot with the two- wheel drive system.
What seems to make the Trilobite different is that it uses sonar (the Roomba uses IR and bumpers), uses magnets in place of Roomba's "virtual wall", and the big thing is that the Trilobite seems to map things and know where it is. The Trilobite says that it can find its way back to it's charging station. The Roomba has no such capability - as far as I can tell, it drives somewhat randomly around the room for a fixed period of time and then claims the room is clean. The Roomba avoid small things by bumping into them and turning away, the Trilobite claims to sense and avoid them.