Tip: Most people are on a schedule. If you ride the same route about the same time every day, the drivers may remember you and retaliate for delaying them or crazy moves that you did the day before. Ride courteously.

Not always possible, but...
Tip: Help the traffic keep moving and lessen road rage (mabe a little)
While traveling in busy rush hour traffic, don't let cars stack up behind you. Rather, ride in a straight line on the side, as a car approaches from behind, signal them to pass (when it is safe to do so).

This works best when the car is about 30' behind you, probably because the driver doesn't have time to get pissed off. I find that when I wave them to pass, my arm is out further and they actually give me more room while passing.