benhoskings/babushka — pull request #218 by sporkd (2012-08-19 05:34:11+00:00)
Title: Use official Command Line Tools for Xcode package

So the supported way to do this now to download the official package from Apple. A small bummer because it requires user intervention to login to Apple's developer site. However, it's guaranteed to work alongside with Xcode installs and will be supported by Apple and Homebrew.

See this post for full details http://kennethreitz.com/xcode-gcc-and-homebrew.html