When's the last time you left a friend a voicemail? If you can't remember, don't worry . . . it means you're POLITE.
--According to an article in the "New York Times", the new rule of cell phone etiquette in this day and age is . . . only leave a voicemail if it's a LIFE-OR-DEATH EMERGENCY.
--Otherwise, hang up and send a text summarizing what you were going to say.
--The theory here is that leaving a voicemail is a BURDEN on the other person. They have to actually go to the trouble of pressing the button and listening to it. And there's nothing you'd say in a voicemail you can't say in a text.