I would think that this is a common design but... I can not find an
example.

I would like to have a page with 2 web parts.
a) a list web part of a specific document library - simple enough
b) a web part that has the pdf viewer in it.

Picture a thin list of documents(pdf) down the left hand site and a
large area to the right that displays the selected document.

Basically, I would like to be able to select a document from the
list "a)" web part and have it rendered in the "b)" web part.
I would like to be dynamic so that as I click up and down and all
around in the list, the appropriate pdf is rendered on the page.

Any ideas or pointers?