For security purposes, Mozilla applications block links to local files (and directories) from remote files. This includes linking to files on your hard drive, on mapped network drives, and accessible via Uniform Naming Convention (UNC) paths. This prevents a number of unpleasant possibilities, including:
The User Agent Switcher extension adds a menu and a toolbar button to switch the user agent of the browser. It is designed for Firefox, Flock and Seamonkey, and will run on any platform that these browsers support including Windows, Mac OS X and Linux.
Screengrab saves entire webpages as images.It will save what you can see in the window, the entire page, just a selection, a particular frame... basically it saves webpages as images.