We have previously seen the installation of the Ghnomix icon theme under Ubuntu 12.04/11.10 manually. This icon theme gets a PPA, so the installation will be now easier than before.
Ghnomix Icon Theme Installation
Open the terminal and run these commands:
sudo add-apt-repository ppa:upubuntu-com/themes
sudo apt-get update
sudo apt-get install ghnomix
You can enable Ghnomix either with this command:
gsettings set org.gnome.desktop.interface icon-theme 'ghnomix'
Or use Gnome Tweak Tool: