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.
It can capture any Java or Flash embedded in a page, but to do this it requires Java to be installed in the browser.
Sadly, there's a bug in 0.96.2 with Firefox 3.6 (due to a deprecated API call - oops!) that causes a crash on any page containing Flash or Applets if you have Java enabled (sort of the reverse of the last major issue). 0.96.3 is finished and waiting for Mozilla approval to be released. That usually takes a few weeks. My sincerest apologies.
The following little keywords are at the request of those who can't remember the name ScreenGrab! and want searches to work. It takes screen shots, screenshots - that is, shots, of web pages.