Stackoverflow.com

A few days ago, stackoverflow.com launched in public beta. I've played with it a bit and I think it has the potential to become a great tool for programmers.

It's basically a combination of blog/wiki/digg/forum. Seems like a most questions get answers (on various degrees of relevance) within minutes-hours. Here are some of the questions I've asked, in case you're interested.

Here's a review of the beta site (about a month old), but instead of reading it I encourage you to just try it next time you need a programming question answered and Google fails you (don't forget to subscribe to your question's RSS feed).