brew tap homebrew/binary
brew install packer
https://www.virtualbox.org/wiki/Downloads
http://www.vagrantup.com/downloads.html
npm install -g bower

cd packer
packer validate ubuntu_12.04_lts_vbox.json
packer build ubuntu_12.04_lts_vbox.json

vagrant box add ubuntu-12.04-x64 ubuntu-12.04-x86_virtualbox.box
cd ..
vagrant up