The JMT (John Muir Trail) does not have cell service for about 98% of the 211 mile trail, common to any hikers doing hiking in remote mountains.
The Iphone is a great multi-purpose device but up to and including the Iphone 4, if you had GPS on, you also minimally had search-for-Edge cell service on (which drains the battery as there is no cell service, so the phone would keep on searching, draining...).
Anyone on the board have an Iphone 4s? I've hated the fact my Iphone 4 does not allow me to have the GPS on without at the same time having Edge search on (I could turn 3G search off but not Edge). This looks like I can turn off all cellular data services-only off and keep the GPS working. Does anyone on the board have a Iphone 4S and can they confirm? I love having the GPS feature on only for times when you want your photo to have the GPS location tags embedded in the photo, and when you're doing passes full of snow for miles. (Otherwise, I'd want the GPS search off.) I have complained to Apple numerous times, maybe they've listened. Anyone know for sure? Ps, do you know about the JMT Harrison map app for the Iphone?
See the article about this: