I love the techgadgets as much as any other guy, but relying on tech alone is asking for headaches. In the U.S., unless you stick to the major Interstates and cities, cell phone service is iffy. And unless you subscribe to some roadside service who do you know to call in unfamiliar territory, if you can find anybody at all?
No Sir, I'll go as prepared as I can and avoid playing the HELP! game on a deserted isle. Though, if I can't throw my horse outta a ditch then Plan Cell Phone comes out.