Beginner XML Project

Hi folks,

I'm a beginner to this technology and need some basic information. I'm a programmer needing to do an xml project for an undergraduate class. This class does not cover xml but the one next semester does. So, this project will be a lead-in for the next class. The instructor has given us carte-blanche to come up with what we choose. I'm looking for ideas on what I could do using xml that will not be too hard but will be a good starting point to learn more. Thanks for any inputs.