This is a reasonably simple Google App Engine which is intended to proxy requests to the Twitter API.

The basic problem it's trying to solve is that if you want to release an application to the public which consumes the Twitter API (and requires oauth), you have to share your oauth application key and secret with everyone who uses the application. Either that, or have each person sign up for their own key and secret.

I faced this problem with my Wordpress plugin which needs to consume the API. I didn't want to include my application key and secret in the sourcecode for the plugin for all to see, so I needed a better solution.