#4 Ubuntu Tweak  in Ubuntu 12.04 - Tools for Tweak Ubuntu This is the tool for Ubuntu to tweak every system settings as you like. This make easy to change hidden system and desktop settings. Ubuntu Tweak is only for Unity Desktop Environment.

sudo add-apt-repository ppa:tualatrix/next sudo apt-get update sudo apt-get install ubuntu-tweak

This will install the great tool for ubuntu. It has a very good pre-configured list of repositories that can be installed with just a few mouse clicks.