Stupid fucking phone etiquette: The person who keeps CALLING MY PHONE but never leaving a message. If I don't recognize your number I'M NOT PICKING UP THE CALL. TAKE A FUCKING HINT. You've called me 15 times in the last two weeks. Do I EVER answer? NO. NO, I DO NOT. EXCEPT BY ACCIDENT WHILE I MUMBLE "LEAVE ME A FUCKING VOICEMAIL MESSAGE."
(And if you're the one calling me, then I revise the entry to: Please leave me a voicemail so I know who you are. :)