easyGestures is an extension for Firefox that lets you keep your browser's most common action buttons always on hand.
Simply click using your mouse's middle button or wheel anywhere to see an intuitive pie menu containing the browser's main action buttons.
In addition, hitting the 'alt' button gives you an empty menu where you can add whatever buttons or bookmarks you want. If you install easyGestures you'll definitely see a change in the way you browse, and be able to move the mouse less.
Added options for changing the order of the contextual menu, fixed support for mouse devices with more than three buttons, and some extra settings.