PPA List for Ubuntu

sun jdk

sudo add-apt-repository ppa:webupd8team/java && sudo apt-get update && sudo apt-get install oracle-java6-installer

Xfce 4.12 PPA in Xubuntu 12.10 or 12.04 
to get proper multi-monitor support 

sudo add-apt-repository ppa:xubuntu-dev/xfce-4.12 && sudo apt-get update && sudo apt-get upgrade

Libre Office  

sudo add-apt-repository ppa:libreoffice/ppa && sudo apt-get update && sudo apt-get install libreoffice