As in lots of horns. I don't know if it was because I got a slightly later than normal start today, leaving the house about 8:15 instead of 7:45, or because it was just nasty out this morning (hot and muggy) but I was honked at more than any other single morning since I've been commuting. Perhaps even more annoying than the presence of so many honky cars is the fact that most of them were the "I'm here" honk that drivers seem to think is a helpful thing.
It would be an exaggeration to say that I wouldn't have been aggravated by long "get the @#$#$ off the road" honks, but at least then you know what you're dealing with. All I got this morning (including from an MTA bus) were timid "hey there" honks that come from a driver tapping the horn because they feel they should be doing something.
As much as my libertarian soul rebels against it, the Parisians may have it right with their "no horn in non-emergency situations" laws. Of course, even if we had laws like that in Baltimore it's not like anyone would pay attention...
Edit 8/01/08 - BikeSnobNYC has a much more entertaining take on the excess of horns and heat making people insane here.