Bitshift

One of my favorite sites, Instructables, has an article detailing How to turn a Roomba into a robotic WiFi signal optimizer. They make use of the new iRobot Create, a Roomba designed for hackers, but I suspect that with some ingenuity and a serial cable or other interface connected to the Roomba's serial port (bet you didn't know they all had one, did you?), this could be achieved with any Roomba.