i dunno if anyone here has seen this yet but it looks promising
uses a wifi adapter that plugs into your obd2 port and talk with your iphone/itouch
DevToaster - Rev - iPhone app development, Great iPhone apps, and more
i was gonna use it on my civic but i sold it after i test drove a 370z
i played around with the free lite version a little bit in my pathfinder and it was pretty cool