I found several websites with ideas for what to do with your old books. Some of these may be objectionable to some people, but I enjoyed seeing them and thought maybe you would, too. So, here goes (click on titles in red to go to linked websites):
Don't like Reading? Read On...
Amazing Book Sculptures
Unusual Books and Book Sculptures
I'm planning on making several of these: Invisible Book Shelf
And, I would love to have one of these: Quiet at the Library