Slick et al,
The GPS functionality of the iPad 3G is NOT dependent on 3G coverage. The 3G model iPads are the only versions with a GPS chipset. The wifi only models use wifi triangulation. If you have a 3G iPad you DON'T need any additional gps hardware.
True, however, a lot of people are still adding a bluetooth GPS puck to the 3G ipads. With the addition of a bluetooth GPS either unit (3G or wifi only models) can be used for off road navigation with out worrying if you will have cell coverage. IMO this negated the need for a 3G model ipad.
There are 3 types of apps you can use on the iPad.
Apps that are 3G dependent like Google Maps. No coverage no mapping.
Not true. If you have a gps puck like mentioned above, you can use the ipad to locate yourself in google earth. In order to use the high res images found in google earth you can download the area you will be traveling ahead of time and store them in the cache for use when no coverage is available. Pretty cool actually. People have been doing this for years with laptops...
For example: GooPs Technologies | GPS Tracking and Navigation for Google Earth
Apps that can cache maps for offline/no coverage like Motion X GPS HD. You download area maps via 3G or wifi prior to loss of coverage or during per planning f the trip.
Apps that carry all the mapping in memory like ScenicMaps. All maps Are ready to go.
The last two types are suitable for off road / remote area navigation.
See above if you want to use google earth.
Sent from my iPad 2 using IH8MUD