ThoughtFix Demos CarMan
ThoughtFix has a great video of CarMan, the new utility by the same team that brought us Canola! CarMan works on the Nokia N800 or 770 and interacts over bluetooth with the ElmScan OBD-II device. OBD-II is a port that is installed in most modern cars so that car owners and service stations can debug their vehicles. CarMan exposes the throttle pressure, speed, engine RPM, fault codes, etc in a slick analog interface.
The OBDKey device works too. (http://www.obdkey.com)