Another OBD tool -- this one for the iPhone...and WiFi.

[theholycow]

http://hackaday.com/2008/09/27/use-rev-on-your-iphone-to-read-your-obd-ii-port

http://devtoaster.com/products/rev

It seems to be vaporware at the moment, and they don't claim to offer MPG readouts.

[Jay2TheRescue]

LOL, iPhone applications... get a Windows Mobile pocket PC such as the AT&T Tilt (Just like mine!) and you can already do stuff like that.

-Jay