I created a couple of Roomba Bluetooth Interfaces.

They work well and were easier to create than the Roomba Serial Interface. Unfortunately, “bluetooth as serial port” on computers seems a little raw. This is both for PC and Mac, though the Mac seems to be a bit more intelligent about it, perhaps because of its Unix core.
It’s pretty cool being able to drive the Roomba around wirelessly.
Update: added a Mac OS X Bluetooth Serial HOWTO


