I know, this puts me in a distinctly fuddy-duddy underclass, but I don't care. When I see people at the grocery store with phone-to-ear deep in conversation about trivialities I feel like asking them, "Why can't you just BE where you ARE?"
Maybe it's the result of my working years when I had to spend a lot of time on the phone, but I don't want the intrusion of phone calls when I'm out and about. There is a certain serenity about being removed from others and free to dwell on the things at hand. I never have to worry about receiving a phone call when I'm driving. I will never have to face the embarrassment of forgetting to turn it off when I'm at a meeting or the fear of forgetting to turn it on and causing concern to family or friends.
Of course, I'm lucky enough that I'm not likely to be needed in any kind of emergency. Sometimes I feel sorry for those who nervously check their cell phone over and over for fear they will miss a call. I'm content to wait until I get home and check my answering machine. This is working for me!