When people are doing the loud talking in stores, restaurants, etc. I like to take out my phone & have an even LOUDER, more dramatic conversation than they could ever possibly have. I mean, CRAZY made up stuff - my friend's string of B&Es that landed him in the clink, affairs that end with someone's house on fire, drug deals gone wrong. It amuses me, and almost always works. (They usually hang up. If they don't I say, "You know, I'm at the store, let me call you back - I HATE BEING ONE OF THOSE PEOPLE BROADCASTING THEIR BUSINESS IN PUBLIC". THAT always works.)
People are crazy with their cell phones. My other pet peeve - just cause I have one doesn't mean I will be available 24-7. I think there are good times to talk, and they are RARE compared with the number of times the darn thing rings. I also hate when I am spending time with a friend & they are spending time with their iPhone contact list. That text is SO important you'll interrupt dinner with me to send it? Grrr.