Cell phones are just like any other tool. You can use them for good or for evil.
Let's say you're on your way to the airport, and you are like me and need to file an ADIZ flight plan. Well, while you're stuck in DC area traffic, you can whip out the ole cell phone, contact the FSS, and get that done. And to those of you who say, what the hell are you doing talking on the phone while you're driving, believe me, when you're going 10 mph tops, you can do it.
Or let's say that the said traffic means you're going to be way late getting to there. Then you can call the folks who you're renting the plane from, and say, hey, I'm going to be late, who's got the plane after me and when? That way you can decide, oh, the hell with it, by the time I get there I'll be able to taxi the plane onto the runway and then I have to give it up for the next person. It saves you fighting all the traffic and then not being able to fly.
But then, cell phones can be used for evil, too. For example, today, when I went to the gym, some dork was yapping on her cell the whole time she was there. That's bad enough, but I gotta know this: who the hell are you calling at 6:45 AM that wants to listen to your nonsense?
Someone finally said, hey, hang that damn thing up, you're annoying all of us.
But seriously, cell phones are a handy tool. Are they a necessity? Nah. But they can be useful.