Original Screengrab! add-on by Andy M for Mozilla Firefox is abandoned now:
Does it mean its death? Of course not! It has been reborn! I brought it back to life!
Now it is called Screengrab (fix version) and works with all Firefox versions.
Installation page: https://addons.mozilla.org/addon/screengrab-fix-version/
What is Screengrab?
Screengrab! saves entire webpages as images. Just right-click on the page you want to grab and look in the "Screengrab" menu.
It will capture what you can see in the window, the entire page, just a selection, a particular frame... basically it saves webpages as images - either to a file, or to the clipboard, or upload to internet.
Mozilla's Pick of the Month!: Screengrab (fix version)
Screengrab is Free Software: please, if you like it, you can support its progress through PayPal.