my git config on Mac OSX

gitconfig

[user]
        name = Stéphane Planquart
        email = stephane@planquart.com
[color]
        branch = auto
        diff = auto
        interactive = auto
        status = auto
[alias]
        st = status
        ci = commit
        co = checkout
        br = branch
[core]
        editor = vim

install-MacOSX.sh

sudo port install git-core +bash_completion

cp /opt/local/etc/bash_completion.d/git ~/.git-bash-completion.sh
echo "[ -f ~/.git-bash-completion.sh ] && . ~/.git-bash-completion.sh" >> ~/.bash_profile
. ~/.bash_profile