Tree of Codes by Jonathan Safran Foer.
The next book on my reading list
(for when I'll actually have time).
Foer took his favorite book, Bruno Schulz's The Street of Crocodiles, and cut out/deleted words to form a new narrative. Each page is die-cut. A perfect example of how form and content are completely married, with one removed the other would fall apart. Rejected by almost all printers it was proposed to, because it was "impossible to make", it was taken on by Visual Editions.