Screengrab! is an extension for Firefox that makes it easy to save a web-page as an image. With it, you can save anything that you can see in a browser window – from a small selection, to a complete page.
Basically Screengrab! let’s you take what you want from a web-page: the entire scrollable document, just the visible bit, or a draggable selection. Screengrab will even save just the contents of an individual frame.
Download: Screengrab! 0.93