I love my android phone and have dozens of great GPS driven apps on it to navigate in the town and off the grid. I'm carrying it with me in the field all the time in the quite rugged OtterBox Defender case, as well as several means of charging its battery... However, it's only a backup. The battery life, antenna sensitivity, and overall reliability are not that good to promote it to a primary navigation unit. So, I'd always recommend to go for a dedicated unit. For example Delorme have quite attractive offers for bundles of their PN series units with their excellent PC mapping software. Garmin offers nice handhelds combined with the FRS/GMRS radio...