I set my cruise control and just keep on going like they aren't there. Then when they pass me I say "It's your ticket, go get it!" and hope like heck I get to see them get pulled over. I never do, though :-(
I usually talk to the other drivers around me, LOL! When someone's tailgating I'll tell them "If you hit my car, my insurance company is going to make you soooorrrrrrryyyyy!"
I am beginning to hate driving with a passion. A few weeks ago I was on my way to work. I was not quite a half mile out of a town, and a minivan decided that they just positively could not be behind the semi (who was probably going to turn off on the truck route in town) another second. So she passed him, and came within a few feet of hitting me head on! I slammed on the brakes and came to almost a complete stop to avoid the accident. If I hadn't, I might not be here to talk about it. Everyone is in such a freaking hurry. The funny thing is that frequently, someone passes me, and then I catch up to them at the stop light. Yup, passing and wasting all that gas got them SO far ahead of me!