This is a general overview (from memory) of the steps I used to install graphite (http://graphite.wikidot.com) on OS X Lion. I think the steps are in order but YMMV. Please fork and fix if you find an error.
curl -kL http://xrl.us/pythonbrewinstall | bash
echo '[[ -s $HOME/.pythonbrew/etc/bashrc ]] && source $HOME/.pythonbrew/etc/bashrc' >> ~/.bashrc
[[ -s $HOME/.pythonbrew/etc/bashrc ]] && source $HOME/.pythonbrew/etc/bashrc
pythonbrew install 2.7.2
pythonbrew use 2.7.2
pythonbrew venv create graphite