GreaseMonkey And Userscripts.org - A way to give useful tools to your Firefox

“Allows you to customize the way a webpage displays using small bits of JavaScript. Hundreds of scripts, for a wide variety of popular sites, are already available at http://userscripts.org. You can write your own scripts, too. Check out http://wiki.greasespot.net/ to get started.”

by “https://addons.mozilla.org/it/firefox/addon/748″

(click on the numbers on the right to change pages)