Interesting. For setting up a "random" trigger you could:

- You could use the RSS trigger and pick a feed which is relatively random. E.g. Reddit front page post matching "cats".

- You could use the NY Times trigger to search for a common news term e.g. "obama"

- You could use soundcloud to trigger on "new public track by someone you follow"

- If you wanted to go crazy, you could get a wemo motion and point it out your window