Cloning this repository:

git clone git://gitorious.org/~emdash/drupal-open-curriculum/emdashs-drupal_6_intro.git emdashs-drupal_6_intro
cd emdashs-drupal_6_intro

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

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