Some useful bundler commands in Rails 3.
gem install bundler #installs bundler bundle install #reads gem list from Gemfile and installs them bundle check #check gem list from Gemfile and sees if any aren't installed yet bundle help #lists available commands bundle install --without=test #like install but ignores test env gems bundle lock #freezes gems to current versions bundle install --relock #unlock gems, update and lock again bundle pack #installs gems locally to vendor/cache