The Internet SocietyThis is the membership organization that helps set the direction for the Internet.
The Internet Engineering Task Force
The people who help build the Internet work together through this organization. The IETF has no "members" because membership is open to everyone, but they do have regular meetings and rules for presenting ideas at those meetings.
The IEEE
Cipher Newsletter (Security and Privacy)The Electronic Frontier FoundationCipher is a great example of a great newsletter published on the Internet.
This organization focuses on the social issues that arise out of building the Internet.
Please Help! Bugtraq at securityfocus (see the forums link)
Ever wonder how software companies find out about what's broken in their products? Bugtraq provides a forum for people to report broken (bugs) or just software that doesn't do the right thing.
San Jose Mercury News: SiliconValley.com
A great example of a newspaper that has been able to adapt to its community. This one is in the middle of "Silicon Valley".