Show us your bookends!  

Napkin holder?
Though it would work quite well as one, it is really a bookend. The bottom of the piece has a label with the maker named: "Philadelphia Manufacturing Company" along with instructions on "how to properly use this bookend".
I did some digging and found a similar patent granted to another company back in 1935:
http://www.google.com/patents?id=igxZAAAAEBAJ&dq=spring+bookend
(I LOVE the Google patent search! So many wonderful items to look at and be inspired by. It has been a great help to me when researching many items I have purchased over the years..)
You have some great bookends yourself!

I stand corrected!
I'm pretty sure mine is a napkin holder, though. It has a half sphere where yours has the slab and coin, and it's shorter. And not labeled as a bookend.
I like the red hand bookends.

I like
Those are the bent metal ones I use. Altho the boy has stolen all of my existing one. We need to go back soon...

Another one by the same designer
I like the red hand one as well. Been looking for one like that and haven't had any luck..
Found one other bookend by the same designer in the link I provided. (Kind of a fun one, with a thermometer in the end!):