setup.git
Clone and run this on a new EC2 instance running Ubuntu 12.04.2 LTS to configure both the machine and your individual development environment as follows:
cd $HOME
sudo apt-get install -y git-core
git clone https://github.com/startup-class/setup.git
./setup/setup.sh
See also http://github.com/startup-class/dotfiles and Startup Engineering Video Lectures 4a/4b for more details.