[akiruno]

"The GL1 Car Diagnostic Gadget will directly connect your vehicle's engine On Board Diagnostics (OBD) data to your iPhone, iPad, or iPod touch. Use your iPhone/iPod touch to read/reset diagnostic codes" ThinkGeek :: GL1 - Vehicle Diagnostics for iPhone/iPad

 

[achilles99]

I had a similar one for my Palm phone, but picked up a standalone unit. When people need to borrow it, it's a lot easier that way.

 

[chidoks]

definitely going to buy this for the ipad

 

[achilles99]

There is a wireless version that is pretty cool, too. Plug in a small box at the OBDII port, and it'll connect to iphone via bluetooth.