No service plan for droid 1, anyway to work GPS

is there away to make a droid 1 gps work even without a service plan. I read that the phone needs service for the turn by turn navigation to work, but i was curious to see if anyone out there knows of a trick or maybe a rom.

I am rooted using Pete's GPA17

Thanks

GPS/maps will work but I doubt that navigation will.
Oh, I should say "will work on wifi"

No service, no data.
- onDroid

I kept my OG Droid when I upgraded to the Droid 3. I put the OG Droid into airplane mode and turned on WiFi and GPS,

On my OG Droid, I am using the app 'Navigation by TeleNav' as this works strictly with GPS and does not require a data connection. I use the 'basic' aka free version. This provides verbal turn-by-turn navigation. I have not used it extensively, but around Richmond, VA it seems to be working fine.

Bob