i'm annoyed by people who don't use cell phones discretely. This includes but isn't limited to talking louder on their cell than with someone right next to them to sound important, loud and obnoxious ringtones, using them when it's inappropriate like at the movies, looking down to see who's calling while driving or riding a bike, and continuous beeps from PTT (push to talk) phones. And i really hate it when i'm helping a customer who's on the phone, and they get mad at me for interrupting their conversation.
There oughta be a law...