Free-soft.org - General information on Free Software (Open Source) and its community.
GNU Help - A group of network architects, designers, developers, and admins offering support to organisations. Includes forum, papers and related links.
Intel Open Source Computer Vision Library - The computer vision library will provide a wide range of functions, including gesture recognition, object-tracking, face recognition and camera calibration, that will help researchers develop ways to use "computer vision" as a method for people to interact with computers.
Open Ideas - User community support to Free Sofware projects, providing a newsboard, forums and wiki, as well as hosting services for mirrors.
Softpanorama - (slightly skeptical) open source software educational society. Eastern European focus; many links are ideal for those with few resources in hardware or money.
Sun Source.net - Site about Sun's involvement in free and open source projects.