Until now I was too afraid at the notion of adding a new PPA to the system. Some sites give you the direct commands to add the PPA but when you have to do it manually, I start to sweat.
Today, I wanted to install HandBrake in my Ubuntu system, and was directed to this page. And after installing the key somehow, I got to know how easy a task it was. All you have to do is type sudo add-apt-repository <ppa-name> and sudo apt-get update after the key is installed. For example, the commands I entered in this case were:
sudo add-apt-repository ppa:stebbins/handbrake-snapshots sudo apt-get update