The merits of the "National Treasure" series of films (2004's "National Treasure" and 2007's "National Treasure: Book of Secrets") are certainly debatable, but the creativity and artistry that went into creating the "Book of Secrets" prop isn't. It's a stunning piece of work, all the more amazing because 95% of it's incredibly detailed contents are never seen on screen. It's creator, Ross MacDonald, has been kind enough to show some of that material at his website and he even offers a an exacting replica of the screen-used prop for sale.
For well over a year there has also been a fan-run project to recreate the book that I was peripherally involved with. That project has now come to a close, but here are some pictures of the numerous documents, pictures, and examples of ephemera included.
Along with the expected material involving the Kennedy assassination and the Roswell UFO crash there are several smaller sections covering secrets drawn from various literary sources. In the upper right corner of the above picture you can see part of my contribution, one of the Elder Thing sketches based on "At the Mountains of Madness" I commissioned from artist Danny Cruz. That's right, the "Book of Secrets" includes a section describing exactly what was discovered during the Miskatonic University expedition to the Antarctic. It includes photographs and sketches drawn from the materials collected by Prof. William Dyer and details the US government's official intelligence involving the matter and their response.
My section is just a small part of the book, dwarfed by the hard work of dozens of contributors that helped make the fan project possible, but it's an amusing Easter Egg for anyone familiar with Lovecraft's story.