Cloning this repository:

git clone git://gitorious.org/gpg-mime-filter/gpg-mime-filter.git gpg-mime-filter
cd gpg-mime-filter

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

git remote add gpg-mime-filter git://gitorious.org/gpg-mime-filter/gpg-mime-filter.git
git fetch gpg-mime-filter
git checkout -b my-local-tracking-branch gpg-mime-filter/master_or_other_branch