Cloning this repository:

git clone git://gitorious.org/0xdroid/external_libsoup.git external_libsoup
cd external_libsoup

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

git remote add external_libsoup git://gitorious.org/0xdroid/external_libsoup.git
git fetch external_libsoup
git checkout -b my-local-tracking-branch external_libsoup/master_or_other_branch