Well, at least I've brought along A Wizard of Earthsea so I can work on my screenplay. Nearly through with the first pass at a "treatment," which is a simple listing of the various scenes I think are important to include. From that, I'll refine a bit and then start actually writing the screenplay.
I'm finding, from my NaNoWriMo experience, that I like having things well planned out before I start writing. If nothing else, it gives me a place to jump to and write something when I'm stuck on the current bit. Previously, I'd attempted to write things more "organically," starting with the first word and going on to the last. I never got very far with that. My characters would just start wandering off with nothing much to do. So I'm hoping that having more structure will give me a better chance of finishing.