Practical Metadata

Currently working on a demonstration of the principles of metadata design. I am considering a resource type of which to use as an example. Please comment if you have suggestions. I want to use something that has not been done many times over (like music). My current thinking is to do metadata design on desktop applications. One ramification of this would be a requirement to change the definition of metadata from just a description of data to a description of an electronic resource (as clearly both applications and services would not be considered data).
Your thoughts and suggestions are welcome...