Oh yeah I know what you mean about cell-phones in the boonies.
Very often they are useless, but people feel safe (and sometimes take stupid risks) because they have one.

Heck, they barely work out on the road where I live.

I suggest toting one along for women mainly as a deterrent . It's not going to stop a hard-core criminal, but the idea of you being in contact with someone else is often enough to spook the merely mischievous. Think "carload of highschool boys" here. If they see you whip out a cell phone while scrutinizing their license plate number, 9 times outta 10 they'll go find someone else to harass.

I've also witnessed them being used to report bad drivers, report vicious dogs, and call for aid in the event of crashes and/or serious mechanicals.