Originally Posted by gunslinger
garmin has an app for Iphone and my understanding is it works without cell coverage.
Those apps should be checking with the GPS chip built in to most cell phones. They won't work with an iPod Touch (iPhone without the phone hardware), which does not
have GPS capability (although there are third-party GPS receivers that plug into Apple's dock connector to give the Touch true GPS capability at the price of battery reserves).
I believe Samsung's answer to the iPod Touch — the Galaxy 4 Player and Galaxy 5 player (both non-phone Android devices) — kept the GPS circuitry from their telephone cousins.