@potterbot is a Twitter bot using so-called Markov chains to generate random new lines. I fed it the complete text corpus of all seven Harry Potter books. When I set it up, I was mostly thinking of generating funny lines, but a surprising thing has happened:
A friend of mine has started replying to the prompts generated by Potterbot, to continue the scenes. You can find a good example here. I find it hilarious, and it’s a good example of creativity produced by human-computer interaction!