This table centerpiece from Style Me Pretty is stunning, simple, and inexpensive!
A hollow book safe is Nancy Drew chic. Make your own, or buy one like this from conduit press.
This gorgeous installation (by Cath of California via simplesong) would be easy to recreate with some styrofoam balls and a circle punch.
If you find your book collection is stacking up around you, turn those piles into a table or fort!
(I've lost the original sites of these last 2 images, if you know who they belong too, please leave a comment so I can give the proper credit.)