Hi, you need a bluetooth GPS module to get GPS on the 770 cost 65 EUR (sorry don't know US prices)
You can use maemo mapper as GPS software, it's free and works very well.


Maemo Mapper has a feature to download maps while driving but I don't know how it works if you use bluetooth gprs. So it might be that you need to get the maps in advance. Also Maemo mapper scans your bluetooth GPS so it is VERY easy to get going with GPS on the N770.

-Tom