How can I browse my pdfs? I have a great many directories where I've latex'd my notes on various topics, so many that I'm beginning to have trouble finding things.  Is there a way to display thumbnails of all the pdfs (under a given parent directory) in a single window so that I can browse my notes?

Also, I've noticed that Mountain Lion is not generating thumbnail icons from my latex pdfs.  Not sure why.
Finder's "All my files" section has pdf-documents category.