Write "deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen" to standard output and append to "/etc/apt/sources.list.d/10gen.list" as root
sudo echo "deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen" | sudo tee -a /etc/apt/sources.list.d/10gen.list