Greg, let me ask you this ettiquette question.............

Are you on your cell phone when your interacting with others? (cashiers, bank tellers, etc)

When I run into people I know, and see them at a table in public, with their heads stuck in their phone while with someone, I give them grief and tell them they don't need to text the person on the other side of the table. But I also find it not only rude, but also not to their benefit, to not be paying attention to who they are dealing with. I've seen order that have been wrong (the taker either thought something they said on the phone was part of the order, or the phone user didn't hear the other party repeat back and incorrect order). Seen at both restaurants and the bank.
I did get a chuckle a couple of times when a casheir (once at a grocery store), just stood their and when the phone user said something, they pointed to us and the line and said we will wait.

Now emergencies happen (seen someone on the phone when they heard their wife went into labor), and in those cases, I just hope they don't drive (distracted driving isn't good).