This reminded me of Google Sets, which has been in Labs forever: http://labs.google.com/sets http://labs.google.com/sets Sure enough, if you ask it to build a

This reminded me of Google Sets, which has been in Labs forever: http://labs.google.com/sets http://labs.google.com/sets Sure enough, if you ask it to build a Square and it can't figure it out, it uses a Sets-like interface to ask you for five examples.