thumbnail images of the site map

In my work flow I find it very useful to create a site map with images of all the web site's pages. I like being able to easily look over how a site looks so that I can post notes about the changes I would like to make to it in Acrobat.

What I would like to know is if there is a extension that lets me do this without taking screen shots of every single page on a site and then individually laying them out in a flowchart program before importing it into Acrobat. Anyone know a extension that would work?