Usually I check the http://www.total-web-design.com forum everyday. its a great community and i enjoy chatting to the people there.
But now since Highbury have gone bust and Imagine has taken over and no one really knows what will happen in the future, some of the members there set up a new forum for us out of the kindness of their hearts, which is great becasuae it means we all get to stay in touch and still get to talk about sheer nonsense.
Anyway i encourage all people who are intersted in web deisgn to check it out. http://www.designersblock.org/forum. Its a great community and with members who have a vast knowledge on just about any area of web design from CSS to Flash to Coldfusion.
So check it out now: www.designersblock.org/forum