Great Little Book Shelf
Thanks to a post left here by a reader, I was made aware of this unique program.
I downloaded the 64 bit .deb version at https://sites.google.com/site/greatlittlebookshelf/
Then I installed it in Ubuntu using gdebi.
It runs very well, and I am impressed with how functional it is, given that it is still in beta.
The only issue I have is that currently it only views pdf format, and I am an epub user.
That aside, I think there is a user base that would love this software package, so I am bringing it to your attention.
The program was written by Dejan Petrovic. (Not to be confused with the tennis pro..)
Here is a video showing the handy-ness of this program:
Here are some screenshots of the program: