Originally Posted by IMOA

On the ground and walking around I have offmaps on the iPhone. You'll need to load the maps before you leave home but even with data roaming turned off the 4S will get a GPS fix in a matter of seconds and you can use that to see exactly where you are even if you are using a map/atlas to do the actual navigation (the atlas pages are much bigger than an iPhone screen)

Originally Posted by OskiBear

I use offmaps on my iphone. if you download the map in advance, the gps in your phone should work to locate you without a data plan. it's not perfect as others have pointed out but i found it works pretty well. I almost use the compass feature more than the physical map itself.