When you're using a minimal Ubuntu install if you find the 'add-apt-repository' command is missing (it's useful for adding PPAs and other repositories), then simply run: sudo apt-get install python-software-properties

If you're a Google chrome user on Ubuntu you may have noticed apt-get update seems to wait around for two minutes sitting at 99%. The culprit is the google apt repo having issues with http/1.1 pipelining. Fortunately there's a bug for it on Launchpad