Yes, there are legitimate reasons to keep your phone on--say, for example, that you need to be reachable at all times by the babysitter. But by and large, attending to one's phone rather to one's companions basically says that "my commitment to you is only partial right now."
Enter the Phone Stack Game, offered below with no additional comment or analyses:
We usually take a pretty hard line against phones at dinner, but a new trick just popped up that gives us hope for the future.
It's called a phone stack, and it's a buzzing, flashing reminder of every phone-etiquette rule the world seems to have forgotten.
It works like this: as you arrive, each person places their phone facedown in the center of the table. (If you're feeling theatrical, you can go for a stack like this one, but it's not required.) As the meal goes on, you'll hear various texts and emails arriving. and you'll do absolutely nothing.
You'll face temptation-maybe even a few involuntary reaches toward the middle of the table-but you'll be bound by the single, all-important rule of the phone stack.
Whoever picks up their phone is footing the bill.
It's a brilliant piece of social engineering, masquerading as a bar game. It takes the phone out of the pocket-where you can sneak a glance and hope nobody notices-and places it in the center of attention at all times.
Suddenly, picking up your phone is the big deal you always secretly knew it was. And more importantly, it comes with consequences.
But if, after the third ring, you decide your call is more important than your lunch tab, we're sure your friends won't object.