A Python Chat Application built using Qt
For Ubuntu: http://www.saltycrane.com/blog/2008/01/how-to-install-pyqt4-on-ubuntu-linux/
For Other OS: http://pyqt.sourceforge.net/Docs/PyQt4/installation.html
Book: Rapid GUI Programming with Python and Qt
Website: http://zetcode.com/gui/pyqt4/