What about bitbucket (for git and mercurial) or Team Foundation Service (for git and TFS (microsoft CVS))? They both provide 5 free private repositories and git support. Also, Bitbucker offers a git client for mac and windows and TFS offers a LOT of project managment tools.
I think bitbucket and tfs aren't as social as github, but if you need private repositories, maybe you want to loose that "socialness"
Hope this bring to the table some ligth.
