Not only accidents. At an airport one day I watched a dad with a little one in tow. The little one was frightened and almost crying, trying to keep up with daddy, evidently wanting her father's reassurance, and the dad was paying NO attention at all because he was angrily busy with a phone call.
I like cell phones (I didn't always, but after 9/11/01 I realized how useful they were), but they can be mistaken for real life. We have to be the bosses of our cell phones and other equipment, instead of having them be the boss of us - no matter what our jobs are or what our friends are doing.
I must mention something else, though. Several years ago, when one of my daughters was in college, she spent a summer with her roommate's family. It was a great excuse for us to visit that part of the country. Roommate's dad was career military, with a high-level job in D.C. which DID actually require him to be on call 24/7. Literally. So he frequently did have to stop for his cell phone. In between those phone calls, even if it was only five-minutes, he was one of the best, most focused, most attentive husbands and fathers I've ever seen. He didn't let his phone or his job detach him from what was more important. His children could count on him, and they loved him (as well as their mama) - and now his grandchildren do, too.