I am currently working on development of an app for the iPhone that includes the maps and data book for the AT. This would be stored on the device so that no wireless conection or signal would be needed to operate. If there were a signal, the app could also interface with Facebook, Whiteblaze and TrailJournals. Also a function of the app could work as a homing device for peace of mind for the family back home. I have a small, lightweight, compact, solar charger called a "SOLIO" that works great on the trail to eliminate battery concerns. The development costs are steep. I already have a prototype, but need to know if this would be a benefit to enough people to make it worth the investment. Please, give me your thoughts.