On repurposing fiction

I"ve been thinking quite a bit lately about different ways to repurpose content. This has come mostly from my delving into the wide world of XML, which is a great thing for publishers to look into, assuming there is some repurposing of content to be done. If you have a properly tagged XML document, it becomes very easy to recycle parts of it, or restructure the whole thing, or just generally mess about with it in new ways. This is great for publishers because as long as you have the electronic rights, you've already got the content.

Repurposing is fairly straightforward for some classes of books: A travel guide, for example, could be pretty easily repurposed into a mobile-based geospatially aware application that could tell you what's across the street from you. Cookbooks, similarly, can become databases that are easily sortable by ingredients, or serving size, or appliances needed, or whatever. Textbook-type nonfiction, where each chapter is a more or less discrete unit, can even be segmented and used in anthologies or as journal articles.

Fiction, it seems to me, is the tricky part. What sort of repurposing can be done with a novel? Certainly, there is some room for customization--one of the vendors at TOC did exactly that, and would sell you a copy of a book for a friend with your friend's name used in the text of the book, or printed on the dedication page. But other than that, I'm at a bit of a loss. I think there's got to be a fascinating way that fiction can take advantage of geospatial recognition to build stories that go different ways depending on where you are, or perhaps on how many other people around you are also reading the same book, but I haven't been able to figure any of them out yet. Any thoughts?