Perhaps some of these cell phone junkies are hyper-active or deluded about their own self importance. Sounds like they need to chill out or take a tranquilizer.
I think you're right. Some people have gone to using these devices (and I use them all, and enjoy them all and am productive with them all) to becoming addicted to them. And they have all the nervous, annoying and irritating habits of any addict.
We do need to get away when we can though and I see both sides of this. I was on call Friday and called my job and told them I was shutting it off for an hour and left a message of where they could reach me. (I have an hour response time) If it's something that will be more than an hour, I'll call and tell people, I'm at the movies. Don't call me unless it is an ER.