The Epsilon website already includes several screencasts and examples that demonstrate the tools and languages it provides. The preview release of the Google App Engine for Java has made it possible to go one step further and allow people to actually write and execute EOL (the core language of Epsilon) programs straight from their browser without needing to download or install anything.
http://www.eclipse.org/gmt/epsilon/live includes an editor where one can write and execute EOL scripts, and a console that captures their output. Apart from playing with the basic features of EOL (variables, control flow structures etc.) one can also query/modify a live EMF model (which for simplicity is Ecore itself). To help you get started, the page also provides a number of ready-to-run scripts as a starting point for further exploration.