ELM 327 OB2 Bluetooth Gauge/Scanner
Chris(LateModel) turned me on to this. I picked one up on Amazon. I know with a Droid its much easier with the app Torque, but for those with a iPhone jail broken this can be done.
I was quite happy with the results. I got Dash Command and it showed me pretty much everything. Just a cheaper alternative for those that are looking.
Anyone else running one?