A dedicated GPS has a lot of features that aren't going to be in a cell phone.
A GPS des not make up for stupid

- re: woman found with dead child in Death Valley. As far as unreasonable maps and directions from a GPS, you have to use common sense. Getting off trail in a place like Death Valley is just plain stupid, even getting off trail at all in your 4wd is asking to get stuck. I have on occasion pulled just to the side of a track and nearly sunk in to the axels. Now I don't even do that. Driving off through sand in an on-road vehicle (even with 4wd) is something that doesn't even seem wrong to people who watch tv commercials and sand climbing and such. Without special tires and the ability to get your self out (like a winch and something like chicken wire to put own on the sand) and going with another vehicle, makes this safe. I had a friend with a new 4wd and he decided to just drive into a snow drift by the road, because he hd 4wd right? Its like setting your cruise control and stepping into the rear of the van.
Jim - having the gear but not a clue doesn't work.