In Rodney Brooks' recommended book Flesh and Machines, he talks about his disappointment over robot lawnmowers. That was five years ago, and little has changed in the field since then. It's pretty much still the same robomowers with the same less-than-killer-app technologies. Brooks' iRobot obviously is hoping to change that with their "Mowba" (let's hope that's a working title) patent filing. Robot Stock News has a bunch of patent illos showing the different possible configurations, moving technologies, sensor types, and mowing schemes.