Cloning this repository:

git clone git://gitorious.org/motorofl/android_system_core.git android_system_core
cd android_system_core

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

git remote add android_system_core git://gitorious.org/motorofl/android_system_core.git
git fetch android_system_core
git checkout -b my-local-tracking-branch android_system_core/master_or_other_branch