I searched the forum and as far as I can tell these haven't been mentioned. They both are really great and free. If you have a Mac, I would recommend giving them a try. They're both contextual menu plugins. With Quickimage you can view, rotate, and edit image files without opening any applications. With Phototool you can view and copy photo exif info, rename files based on exif date, and more. Here's the link :http://www.pixture.com/software/macosx.php
(I have no relationship with the makers of this software; just wanted to pass this along).