From time to time, I get honked at even when I'm riding safely and legally. I think the car driver is just angered at losing a few seconds of his or her precious time stuck behind a "toy" riding on the street. This seems more common in cities and towns with fewer cyclists. It's easy to be a bully when you are encased in steel and the object of your aggression is some person poor, silly, or stupid enough to ride a bicycle on the street.
Getting honked at is often starting and can be very dangerous. I suppose that the best response is to just ignore it and not let it bother you. How many of you race to catch up with the driver at the next light to yell or explain our rights to the driver? Does it do much good? Do you just smile and wave? Any advice on how to handle this without making my blood boil???