As the AJAX API Playground is built on App Engine, you can create your own App Engine instance to show off your code samples. The code is open sourced under an Apache 2.0 license and uses several open source libraries and tools, including jQuery, jQuery UI, YUI Compressor, and CodeMirror. You can find the code on Google Project Hosting and learn about adding samples on the project wiki.
Stay tuned for more samples for more APIs. Enjoy!