Normally, when you hover over links, you can view the address behind that link in the Firefox status bar (at the bottom of the screen). If you don't use the status bar for something else, you can remove it (View -> Status Bar) for gaining a few extra pixels in screen height, and still keep this mouse over links showing the URL behaviour, by using a neat little Firefox add-on called Status Address Bar.
REFERENCES
http://www.webupd8.org/2009/10/remove-firefox-status-bar-keeping-mouse.html
REFERENCES
http://www.webupd8.org/2009/10/remove-firefox-status-bar-keeping-mouse.html
