What Font Is - Find any font from any image (commercial or free)
Imagus - The extension is intended to complement image features that (I think) is missing from Opera by...
AMP Font Viewer - Jump to Download - Download.
Thumbnail Zoom Plus - The official site of the Thumbnail Zoom Plus add-on for Firefox
Font Viewer - Font Viewer is an application which does exactly that - it views fonts!
Image Max URL - Help find larger or original versions of images, including a customizable image popup feature