Sugu and I had an idea like this, but I suppose it was inevitable. I have my own thoughts on how to make these kind of innovations work in my own books, so I'll keep them to myself for now (mostly revolves around including ten dollar bills in the jacket of every copy).
The Lord of the Rings honeymoon is over.
Wrote four pages to finish chapter 20 tonight, bringing the book up to 471 pages. Got to the sword fight tonight. As Joss Whedon once said, there's a sword fight because you have to have a sword fight. I suppose that makes the book PG-13.