I had my first "real" commute "race" yesterday afternoon.
The second half of my commute begins with a decent climb of a mile or so. As I get about 2/3 of the way up, I come up on this guy, obviously commuting as well, going considerably slower than me, so I say "On your left" and go to pass. He gets huffy with me and cracks some smart-butt comment about "Nice warning, pal!" I guess in addition to being slow, he was also deaf. Anyway, I just kinda blew it off and kept spinning. Well wouldn't you know that he tries to dial it up and keep me from passing. I get in front, and he starts sucking wheel like a job. Overlapping. Dangerous. Sorry pal, not going to fly. I shifted up a couple of gears and stood up to dance the rest of the way up the hill. Hit the big ring at the top, and started cranking. Look back, and he's doing his best to catch me. I hit it hard on a short descent, and keep my momentum for the next short climb. Dude was toast at that point.
I felt vindicated. I'm not some hotshot wannabe racer or anything, but if you start riding dangerously around me, and act like you have a bone to pick with me for some perceived slight against your manhood or whatever, prepare for the DROP-O-RAMA.