Teaching NHW11 to a USB OBDII scanner

I read in another thread that Bob Wilson has a Graham scanner and has put some effort into getting a USB OBDII scanner to offer similar function. Perhaps others are working on that too. I've been contemplating such an effort myself (about at the stage of having learned a little about the protocols, mostly from the elm327 data sheet, and confirmed on the wiring diagram that all the ECUs I'd like to talk with are sharing the K line, so I assume that the chief obstacle is simply knowing the addresses they respond on, and PID/scaling/units tables ... ?)

So maybe it would make sense to coordinate efforts? Is there anybody who'd be interested in filling me in on what's solved and unsolved to date? Has it proven feasible to run an elm as a promiscuous listener while scanning with a THHT or Graham scanner? Or configure an elm as an ECU simulator to see how a THHT displays data received? (Does anybody have access to a THHT that could be used for that?)

-Chap