An idea for teaching everyone programming using twitter.
Why not adapt this idea to programming? For example, you could allow twitter users to write python programs that fit in 140 characters.
Such programs would execute in your twitter reader by default, sandboxed and with a time limit. This would be particularly compelling if you have access to a graphics library and can create cool patterns in your tweets.
People can learn what these programs do by example and adapt them for their own tweets.