Anyway, there exists a new question and answer site specifically built for programmers called Stack Overflow. This sort of thing already exists in other forms, but Stack Overflow was built with all the lessons of the previous ones in mind. They describe themselves as a combination of a wiki, a blog, digg/reddit, and a forum. People log on, ask questions, and (potentially) thousands of people see the question and can submit an answer. How does this actually sustain itself? It's rather geeky: Reputation points. People who answer questions get reptutation points for giving good answers that are voted "up" by other people. If other people think you give good answers, your reputation score goes up. The details are a bit more involved than that, but that's the general idea.
I managed to get into the beta test reasonably early on (a couple of months ago), and I've been actively participating since then. It only takes a few minutes to check to see whether there is anything new in my areas of interest, and fire off an answer if I happen to be able to. Sometimes I give quick, to-the-point answers, but more often I spend a bit more time to explain the problem and solution, in the hopes that it will be useful to more than one person in the future. Questions and answers will stay online indefinitely, so Google will quickly be able to point people to the answer page for a given question.
If you're a programmer and you happen to have a question that you can't find the answer to, do give Stack Overflow a try. It's amazing how quickly even the most obscure questions get real, thoughtful answers from people who actually know what they're talking about.