In Boston it's a fairly mellow affair, just riding around steadily but relatively aimlessly. The suggestion to hop on I-90 got basically no play, so we're not up to Toronto standards yet. No trouble with the po-pos, and 2-3 times as many people honking their horns rhythmically in approval as people honking in irritation.
I would estimate 100 people. We stopped for almost no red lights, and nearly every intersection got corked. Corkers get thanks from everybody and the opportunity to represent the group, so my intention as a new guy is to do a fair amount of corking next month and be as friendly about it as possible, maybe bring some candy or prizes to give away to motorists.
I expended a little energy on the ethics of the situation and concluded that I'm pretty happy with it:
* In the city, average traffic speed is determined by lights, not peak speed (as much as car people love to race each other to the next traffic jam)—we never had cars bunched up behind us for longer than one light, and my usual commute through the same area is a few minutes faster by bike than by car (even when scrupulously obeying the law), since one guy waiting to turn doesn't necessarily make me miss a light.
* Per light, we're generally holding up 1-10 cars (1.1 - 11 people?) for 100+ people on bikes. While it's against the traffic rules, the 10+:1 utility factor suggests we're justified in disregarding those.
Route: Copley (~5:55) -> Boylston -> Charles -> Beacon -> Gloucester -> Newbury -> Mass Ave -> Prospect (looping around via Inman) -> Broadway -> (hi ocschwar!) Brattle Square -> Mt Auburn -> Putnam -> Sidney -> BU Bridge -> Union Square (Allston), at which point I forked off to feed the hungry (maru_mari, waiting at Harvard Square).
* recumbents: 0
* folders: 1
* fixies: umpteen (yo!)
* rusty-ass ten-speeds: umpteen and a half
* road bike guys with body condoms: at least a couple
* freaky custom choppers: 0 (!?)
so next month I will need to get 'bent. That will involve at least a little brake-cable repair, but if anybody wants to donate a serious battery-powered boom box, I won't complain.