This is along the same lines as the free Autozone engine code reading thread. I found it a while back and didn't think to post it even though it's a smoking deal IMO. You get the hardware for ~$85 and free software. It works, I've tried it.
Check out:
http://www.guentchev.com/OBD-II/
-Kurt
Check out:
http://www.guentchev.com/OBD-II/
-Kurt