Some of the coolest decorations I've seen is at Tashas (delicious pizzas and pastas) in (new) Rosebank, Jo'burg. It really spoke to my booklover's heart. I haven't tried to make this myself, but I'm sure with some skill, a few beautiful old books, glue, and a passion for the written word, someone like me could put this together.
I'm not sure what they should be described as. Book-tree-houses (since they hand from the ceiling?).
Cam-cam, I think you should make this, btw!