When it came time to pick last quarter's application, I wanted to work with YouTube's APIs for two reasons: I have a background in video (as a filmmaker and as a software designer) and I wanted to share family videos with my oldest brother, who is hard of hearing and learning disabled. Fast forward a few months later and I had CaptionTube, an application for creating captions for YouTube videos. CaptionTube has launched on TestTube and Hiroto has written a post about it on the YouTube blog.
In addition to the YouTube Data and Player APIs, the application is hosted on Google App Engine and uses the Datastore, Google Accounts, Mail, and URLFetch Python APIs. I used several open source software projects to create it: Django and jQuery, and app-engine-patch. If you are attending Google I/O in May and would like to ask me questions about my experience or discuss your experience using Google's developer's products, please look for me in the developer sandbox or office hour sessions.