If someone flipped me off, I'd laugh. Also, I'm not a slow driver, so if someone gets right up my ass, I'll usually slow down to further annoy them, and if it wouldn't fuck up my precious car, I'd slam on the brakes and let them have a sweet little ticket. Getting back to the OP, more than likely, you deserved it, so take responsibility for yourself and deal with shit like a man, not a little boy. Also, where's your sense of humor?
As for me, I tend to tailgate them and follow them to wherever they're going just to scare them -- that is, if I have time on my hands. Sure it's a waste of gas, but it's totally worth it watching the driver get nervous.
...until you pull into your driveway and realize too late that they've turned it around.
I'd probably not even notice, but if I did, I'd likely choose one of these: