With the clear knowledge upfront that cell phone reception is iffy to non-existent in many places along the trail, are there any iPhone apps a thru-hiker might find useful? I have a few that I already use: Audible for listening to audio books, "Where" and "Around Me'- for finding ATMs, laundromats, grocery stores etc while in town, Map my Hike for distance calculations on or off trail (e.g., walking into town if you can't get a hitch), "Forum Runner" for keeping up with whiteblaze.net, various weather apps, "MotionX GPS" for GPS stuff, "KIndle" for reading ebooks. Any more suggestions?