I love stackoverflow.com. If you do any programming at all you must check it out. I had a really tough programming bug last Friday and posted a question on stackoverflow with the appropriate tags to help with classifying the questions. Within an hour I had two excellent responses one of which was from Python luminary, Alex Martelli. (His answer turned out to be correct -- no surpise there.)
A feature that I particularly like about stackoverflow is that I can use my OpenID credentials to authenticate. Beyond that, I can link my accounts to their sister site at serverfault.com.
These sites are always the ones that I look at first now for answers even before google! Well done!