Originally Posted by
DevilAlumna
My phone, AT&T branded HTC Raphael, has a GPS receiver in it, and I use the Bing Mobile app for navigation. It also does turn-by-turn directioning, aerial & birds-eye views, etc.
While I can get a GPS track wherever, regardless of cell signal availability, the mobile app uses the data connection to download the maps of where the GPS says you're located. The phone, obviously, doesn't have enough memory to store a country's worth of detailed data.
So, assuming the Google nav works the same way, you can be located by GPS, but need a cell signal to view it. YMMV.