How to: Add launchpad PPA repository to Ubuntu

By using a command line terminal:

# this will install add-apt-repository
sudo apt-get install -y software-properties-common

# syntax
sudo add-apt-repository ppa:[USERNAME]/[REPOSITORY NAME]

# example:
sudo add-apt-repository ppa:ubuntu-wine/ppa

reference:
http://www.ubuntu.com/
wiki ppa