Collaborate/Develop/Share Source Code @ www.codeplex.com

If you are a hobbiest, student, or professional/acedemic developer and like sites such as GotDotNet.com's Workspaces, SourceForge, etc... you should also check out http://www.codeplex.com/. You can create community development projects and/or participate in a community development project that already exists. This is a great way to get connected with other developers, share best practices, and create some really cool and freely available software.