I screen.
I only have a handful of people call me anyway due to my years and years of bad phone etiquette. Finally my CONSTANT VIGILANCE has paid off.
I once had a telemarketer call me 8 times in one night. On the last one of the night, I finally pick up the phone with "You're quite the persistent little monkey aren't you?" followed by a Spongebob Squarepants/Jihad yell. (I don't know if that's the proper description, but the Spongebob fans know what I'm talking about, right?)
He hasn't called back yet....