MIT's Technology Review did a nice short article about Roombas and hacking.
One Bluetooth-enabled Roomba was given a green fabric pelt and was used in a real-life Frogger game at the SXSW Interactive conference in Austin, TX, this year, and ThingM's Tod E. Kurt is collaborating on a live-action Pac-Man re-creation, with reprogrammed Roombas dressed up as Pac-Man and ghosts, navigating a maze and vacuuming up tissue paper dots.
The key part of the article is the popup "Roomba tour" (click on the "click here" link in the article). Thank you, MIT review. Go Tod!