No 1. Is it an emergency? Let me help you determine if it is an emergency... Blood? Car accident? ANYTHING involving my kids? I'll be generous and include running out of gas and needing help with pretty much anything I know how to do as "an emergency", but you need to say so in your voicemail.
No 2. Maybe not an emergency, but do you need to leave me fairly pertinant information; a phone number, meeting time, etc? This is obvious.
No 3. This is the one that gets me in trouble- are you the person I'm sleeping with? If so, you should know that your "Hey... call me back"s are nice, and sometimes your blips of rediculousness on my voicemail makes me laugh until I worry about peeing my pants. And it's always good to laugh.
So, to recap- Are you calling about an emergency/issue regarding my kids? Need to leave me a 10 sec bit of info? Keep a tootbrush at my house?
Ok, then. If we're not dealing with any of those situation, hang up the phone when you get my voicemail. I WILL call you back, I promise. ;-)