Cloning this repository:

git clone git://gitorious.org/~pwicks/drupal-open-curriculum/pwickss-drupal_6_intro.git pwickss-drupal_6_intro
cd pwickss-drupal_6_intro

Add this repository as a remote to an existing local repository:

git remote add pwickss-drupal_6_intro git://gitorious.org/~pwicks/drupal-open-curriculum/pwickss-drupal_6_intro.git
git fetch pwickss-drupal_6_intro
git checkout -b my-local-tracking-branch pwickss-drupal_6_intro/master_or_other_branch