This morning I stumbled upon a pretty useful online app: WriteMaps.
WriteMaps is a free web-based tool that allows you to create, edit and share sitemaps online. It looks and feels a lot like the genealogy site Geni—which makes a lot of sense since a sitemap is very similar to a family tree (pages having parents, grandparents, siblings, etc.).
All you have to do is sit down and play with it for a few minutes to see how useful of a product this is.