When it comes to Shadow Boxes As Art, there's no one better than Tracy W. Hambley. I first saw her boxes in Mary Englebreit's magazine years ago and I've never forgotten them. See what you think, here's Tracy's blog.
Wouldn't it be great to have a box designed around some sort of central literary topic? A scene from a favorite book? A favorite reading genre? A favorite author? A favorite book cover? The mind wanders, but you get the gist of what I'm saying - right? It would be a very cool thing.
Here are some topics off the top of my head: Agatha Christie, Harry Potter, Alice in Wonderland, Nancy Drew, your favorite vampire novel...see where I'm going with this?