Sam Joyce, I really like that notebook concept. Imagine, you have to keep writing or you will die. Sort of like that Speed movie with the bus. I can imagine a short film of that: some friends come upon another friend -- maybe they are meeting the latter for a party, and they are bringing some beer or something -- and they see that the friend is in a panic, sitting in a chair, sweating, writing frantically. The person says, "If I stop writing, I will die!" You get the picture. I can imagine someone taking over for the friend to give him a rest. I can also imagine them trying to trick someone else into writing.
Anyway, just some thoughts. Really good two-sentence story.