Some of us around the Lab have been using GitHub for a while now, and we love it. (It's currently in beta, but we've got some invitations if you're interested in checking it out - just leave a comment here.) Unlike at least one of the alternatives, however, GH won't be entirely free once it launches. Finally, we have some details on their pricing plans. All in all, I'd say it looks very reasonable - 100 MB of space for the free account is plenty given git's efficiency, unless you're storing media in your repository. I also love the focus on open source projects and public repositories, which are always unlimited. I think GitHub's clearly on the right track, and I'm looking forward to seeing how it grows.