The 12th Carnival of Mathematics is up, and it has some nice links, though I haven't looked at all of them yet. Look for the 13th right here in two weeks' time! By then I hope to have at least one new page added to the Advanced High School Math project: the most brilliant mathematical modeling problem (at the high school level, anyway) that I've ever seen.
I hope you're not superstitious about that whole #13 thing. I'm not. Really. I'm not. No, really.