Ohloh is a site I've bumped into before, but never really explored it or created an account. Today I signed up and tried it out, and I'm very glad I did. Project tracking meets resume building meets social networking--I've originated or contributed to quite a few open source projects, and this site gives me an easy overview of the work I've done, what languages I've used, and who else is contributing to or using my software.
Okay, I admit it; I'm not ashamed. I love to write documentation. Most of the time, I would rather write docs than code. That's one of the reasons I was thrilled to discover Read the Docs, a new website that makes it easy for developers to build and publish documentation. You can create quick one-off docs, or link up to existing docs you may have in a public Git, Mercurial, Subversion, or Bazaar repository.