Mailing Lists:

 

 
User Groups:

 

 
Discussion Boards:
GIMPTalk
http://www.gimptalk.com/
GT (GimpTalk.com) was formed in Dec 2004, in a hope that it will help the gimp users and will provide quality tutorials & resources, alongwith a good community forum where gimp users can discuss/help eachother
 

 

 
Chat Rooms:
IRC: FreeNode.net #gimp