The Motorcyclist's Guide to Getting Rid of Tailgaters

There is a car two feet off my rear tire...

Level One
Flash your tail light. This is easy for me, I have a device installed on the R11S that modulates my tail light high/low for ten seconds before going to solid-on. Any of my other bikes, just tap the rear brake rhythmicly. You'll either get their attention, or send them into convulsions.

Tailgater still there?

Level Two
Swerve in your lane like a drunken fool. Usually I can do this well enough to get my rear to pitch out a bit and howl the tires.

I rarely have to go beyond this step. I do not like doing this in rush-hour traffic because it eats up traction and stability I may need to take evasive action when some slow-witted cager swerves into the 65mph commuter lane at .002 mph without a signal. (Very common in Califorina.)

Tailgater still there?

Level Three
Backfire your pipe! This works on most of my bikes, not on the R11S of course, being fuel-injected. A simply amazing amount of fire comes out of the cans on the Monster. It is simple - killswitch to OFF, roll open the throttle, close the throttle, killswitch to ON, . Very effective at removing tailgaters and bending exhaust valves.

I personally do not do this next step. I recommend you do not do it either, of course not...
I do have a friend who likes to spin around with a pointed-index-finger, thumb raised, and make a recoil motion timed with the exhaust explosion. With a black-gloved hand I would imagine this would cause soiled shorts and cellphones ringing to the CHP. At Your Own Risk Johnny Squid!

Tailgater still there?

Level Four
Try your lucky fishing weight. I carry a few 'lucky' 1 ounce lead fishing weights. They can be purchased at any sporting-goods store for pennies. The type I buy is in the typical pyramid configuration with a small wire loop at the tip. This makes it easy to tie them within close reach on your motorbike. Usually I'll snap one off and drop it for good luck. They tend to bounce back nicely resulting in a loud THUNK that makes the tailgater think my bike is falling apart, or at least wakes them from their slobbering stupor. Don't toss the weight over your shoulder as this shows pretty obvious intent to Do Some Harm and might shatter a windshield.

Tailgater still there?

Level Five
Start The Fireworks. I'm lucky enough to have a couple bikes that have nice center-stands. If the BDC has still not got a clue by this point it is obvious that drastic measures are going to be required to unglue them from exhaust-can-rivet-serial-number-reading distance. With my left boot, I reach back to my center-stand and apply light pressure until it makes firm contact with the road surface. This usually results in an impressive shower of sparks. It also results in an impressive display of braking ability from the BDC as they now think I am About To Explode. -This Always Works-
Disclaimer: I would not recommend you do this if your center-stand is hook-shaped, ie: --) when in contact with the asphalt. This will result in a most-impressive aircraft-carrier-landing stop on your part (or it will simply rip off your center-stand) should you encounter a ridge in the asphalt. Both of which will of course get rid of the tailgater, but not in a motorcyclist-friendly manner!

Tailgater still there?

Level Six
Slow down to a dead stop. I don't like doing this too much because now I'm running slower than the flow of traffic and at the mercy of everything comming at me from six-o-clock. And this only works on multi-lane roads where the idiot in the car can whip around you once they become annoyed with your rate of deceleration. It also opens you up to a vengful cut-off attack once they get by. You have the option of really dropping anchor once they make the pass to try and avoid this. But most likely another unobservant motorist will run gobsmack into the back of you at this point.

On a twisty one-lane road with no run-off this technique does not work at all.

Perhaps a little extreme...
drinkypoo says: A better thing to drop than lead weights would be some of the larger non-essential (IE, you could limp home) nuts and/or bolts which are installed on your bike. If it should go through the windshield it would be nice to have it be something that actually could fall off the bike. Alternately, used spark plugs are something you could conceivably have on your person.

NB: No responsibility can be taken for loss of life or limb :)