I love old books and I use them quiet a bit in my Collages. I am lucky that there is a fantastic second hand book store in Galway Charlie Byrnes. I see on their web site they sell books to use as furniture, I've noticed this recently, The Mornington Hotel in Stockholm did this very effectively. I have also seen window displays with thousands of books used as props.
I especially like the illustrations in old books, Here are some photos from a book I have, even the sticker on the inside page is a thing of beauty.