One of the most valuable things to have at any time is an up-to-date list of important pages and the links between them. Dreamweaver CS3 can help you with this by letting you organize your application files maintaining links between all the templates in your project. But sometimes there’s just no replacement for a proper paper document (perhaps a Visio drawing) that you can keep pegged to your wall for reference.
If you keep your page-flow document up to date throughout, you’ll have that much more to refer to if you need to make adjustments to the application a year from now. And let’s not forget that clients and bosses always like to see documents with recent dates on them, no matter what’s actually in the documents.