Driver cuts of cyclist in traffic. Words are exchanged. Cyclist opens passenger door of pickup truck and pulls passenger from truck, attacking him in the process. Cyclist arrested. Read the details here.
Cyclelicious understands the cyclist's reaction but does not recommend this method of cyclist advocacy. If a motorist ticks you off, realize he's probably just stupid instead of purposefully antagonistic. Take a chill pill, relax, and remember that you're having way more fun than the driver is.
If that doesn't work, you can always read the adventures of Spike Bike and fantasize.