30 Boxes has taken its beta public, so if you're looking for a Web2.0-hipster-compliant online calendar with a crazy feature set, check it out. In truth, I was hoping Google would have something like this out by now. I have a hard time imagining them doing a better job than 30 Boxes has already done, though.
(I'm signed up with my Gmail account, if you want to make me a buddy, yo.)