Cloning this repository:

git clone git://gitorious.org/~hoffmann/protovis/hoffmanns-protovis.git hoffmanns-protovis
cd hoffmanns-protovis

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

git remote add hoffmanns-protovis git://gitorious.org/~hoffmann/protovis/hoffmanns-protovis.git
git fetch hoffmanns-protovis
git checkout -b my-local-tracking-branch hoffmanns-protovis/master_or_other_branch