WordPress Answers is a StackExchange Q&A site which has just gone into public beta. If you develop WordPress themes or plugins and generally get your hands dirty with WordPress stuff you’re going to want to go and check it out.
If you’ve never used any of the StackExchange sites (one of the most well known being Stackoverflow) then I think you’ll find that they provide a really good environment for asking questions if you’re in need of help. I’d encourage you to get involved and try and help answer other people’s questions, there’s more and more being asked and you just might be the person who’s written a piece of code or tried out a plugin that will help somebody solve their problem!