This is my idea. As you can see, it is a pen that can not only be used as an extremely responsive stylus that can operate on most surfaces, and can be used to trace things, but it can also be used to detect what someone is writing. As an example, you can leave it in a hotel room, and trick someone in to using it. You can trace a signature or someone's handwriting and match it up to a database, or you can take a picture and trace the photo from in the field. You can send messages, you can store information for later use, the possibilities stretch on and on.