I recently got a Zire72 (PalmOS) PDA, and have a bluetooth GPSR on order for use with it. The mapopolis mapping software seems adequate -- I used the 9-day free-trial maps, and last night paid the fee for the whole shebang (Canada and Bushland).

I'm hoping to jury rig a mounting system for the PDA so I can fingerprint the screen while driving. Mapopolis also includes auto-routing and voice prompts etc.. as well as maps of much of Europe. Looks useful.

Oddly enough, there are only 5 bytes different between their demo maps and the paid maps -- identical file sizes, too.

Cheers