JPEG image of Shakespeare which is also a zip file containing his complete works
Just tried it out and it does indeed work.  curl 'https://pbs.twimg.com/media/DqteCf6WsAAhqwV.jpg' > shakespeare.zip
  unzip shakespeare.zip
  unrar e shakespeare.part001.rar

I'm excited for the inevitable curl | unzip | bash method of installing software directly from twitter that is sure to follow.