just came across this on another forum and was curious is anyone has tried this on here. it basically looks like an app that will transform your iphone or itouch into a scan tool. with a obd2 connector (which you can get wireless aswell for direct wifi connection to your iphone/itouch) you can monitor real time data such as sensors..get fuel mileage etc. and also check and clear check engine light codes. looks pretty promising. would sure beat lugging the laptop around with you when you're out cruising...check it out.

http://www.plxkiwi.com/kiwiwifi/software.html
http://www.devtoaster.com/products/rev/