I have to say I think the flyers/fake tickets are the way to go. Those at least leave no doubt as to why they were received. When all the other tactics that have been listed are employed, there's no guarantee that the offender is going to realize why it happened, and as a matter of fact will probably drive off wondering why someone ELSE just behaved like an @$$hole "for no good reason".

I see it all the time when confronted with tailgaters. When speeding up or slowing down doesn't work to get someone (usually talking on a cell phone) off my rear bumper, I just wait for an opening in oncoming traffic, move into the other lane, hit my brakes, and MAKE the tailgater move in front of me. But almost invariably, it's the tailgater who watches what I do, then drives on with a look on his/her face like they've just witnessed the actions of someone who has no idea how to drive correctly.

I just think some of these more subtly employed tactics are lost on the types of individuals in question, whether it be tailgaters on cell phones who probably can't walk and chew gum at the same time, or parking lot morons who apparently think their name is painted on every space.