Stack Overflow is a great new programmer Q & A site from Jeff Atwood and Joel Spolsky. I (and about 500 other developers) got a 5-week headstart on using it as part of the private beta test. As good as googling for answers to development problems has been, Stack Overflow is a big improvement. I’ve already gotten answers to questions that I was able to use in my own work.
If you write code for a living, I strongly encourage you to check out the site. They support OpenID, so you can use your existing Yahoo! or Blogger (other other OpenID-compliant) identity to register with the site. You can use it anonymously as well.