Based on http://vimcasts.org/episodes/synchronizing-plugins-with-git-submodules-and-pathogen/

git clone http://github.com/dudarev/dotvim.git ~/.vim
ln -s ~/.vim/vimrc ~/.vimrc
ln -s ~/.vim/gvimrc ~/.gvimrc
git submodule init
git submodule update

Update all bundled modules

git submodule foreach git pull origin master

Install a new bundle

git submodule add http://github.com/tpope/vim-fugitive.git bundle/fugitive
git add .
git commit -m "Install Fugitive.vim bundle as a submodule."

To remove a submodule

1. Delete the relevant section from the .gitmodules file.
2. Delete the relevant section from .git/config.
3. Run git rm --cached path_to_submodule (no trailing slash).
4. Commit and delete the now untracked submodule files.