I found that
this tutorial was great for unlocking the radio on my Verizon HTC Touch. I'm now running NFSFan's WM6.5 ROM with the newest radio, found in
this thread, and can get directions wherever with Garmin without having a data plan. I had an unusual problem after following the tutorial wherein I was stuck roaming all the time, but if you have trouble with that I know the fix, so...no worries. Hopefully that helps, since I had a heck of a time figuring out how to get GPS working myself. Good luck.
-Snowden