Cool. I was wondering what those were for! (Assumed factory diagnostics.)

You might also consider a USB to Serial adapter (which are extremely common nowadays). Somewhere -- oh yeah, HERE -- there are instructions on how to turn your 770 into a USB host, allowing it to access peripherals like keyboards, thumb drives, and (maybe?) USB to serial adapters. (I would think that would expose itself as a regular serial port, whatever /dev/??? that translates to.)

Keep in mind that you must supply 5v to the USB cable somehow. There are a few cables out there you can purchase (like those for mini external hard drives) that allow you to inject power, or you can just splice your own. If you can solder, you will have no problem.

Good luck, and let us know if you go this route. I'm curious to see if it exposes itself as a serial port. I would also like to see if it would work with a serial OBDII scanner and that maemo-based OBD software.

Incidentally, I have one of those USB to dual-PS2 adapters, and although I didn't hook a mouse up, hooking up a PS2 keyboard worked perfectly.