Initial installation:

  git clone git://github.com/mwilden/vim.git ~/.vim
  ln -s ~/.vim/vimrc ~/.vimrc
  cd ~/.vim
  git submodule update --init

Add bundle:

  cd ~/.vim
  git submodule add <plugin-repository-url> bundle/<plugin-name>
  git add .
  git commit -m "Add plugin"

Update bundle:

  cd ~/.vim/bundle/<plugin-name>
  git pull origin master

Update all bundles:
  cd ~/.vim
  git submodule foreach git pull origin master

Remove bundle:

  Remove it from .gitmodules
  Remove it from .git/config
  git rm --cached bundle/<plugin-name>
  git commit -a "Remove plugin"
  git push

or

  rm -rf <path-to-module>

To resurrect after deleting the bundle directory:
1. Look in gitx to see the name
2. git co bundle/foo
3. git submodule update -- bundle/foo