I found a program the other day that at least is WM6 compatible...OBDMobile. It is on Windows Marketplace. Link:
RKlenka - View topic - OBDMobile is on Windows Mobile Marketplace! OBDGauge did install on my Tilt
OBD Gauge , but I do not have a serial cable for it. I also looked at OBDPro and their adapters
OBDPros , as well as BLueOBD
blueOBD - bluetooth project based on OBD-2 , OBDKey
OBDKey :: Wired and Wireless Automotive (OBD) Scan Tools ...but most of those require some dollars.
Are you looking for something to interact with the vehicle, or just something to log data into? How about tweaking an MS Excel spreadsheet?
Here are a couple other sites I've visited:
WinODB - Ordinateur de bord pour Windows Mobile
OBD-2 Vehicle Explorer Scan Tool Browser
OBD Diagnostics, Inc. - Diagnostic Software lots of stuff here...