From Codemii:

XML files are used as an easy way to read and store data which is useful for storing configuration settings from applications. It’s always good practice to allow your application to be customised by the user, be it by turning off the Wiimote rumble, enabling background music, disabling prompts, etc. In this tutorial we’ll learn how to load and save simple settings by using XML files.

http://www.codemii.com/2009/06/21/tu...ple-xml-files/