Hopefully, you already know about StackOverflow (if you don’t, you owe it to yourself to go and check it out right now!).
But did you know that there’s a new User Interface Stack Exchange?
Currently (October 2010) still in beta, this site is fast becoming a great place to go for advice on user interface and user interaction design.
One good example is a question of mine - What is a better way for users to select a date range? - to which I’ve received a number of high quality answers that I’m going to put to good use.
Go check out the User Interface Stack Exchange and start participating today.