Userscripts.org

// ==UserScript==
// @name           Opacity pages
// @namespace      http://www.gaiatools.com/p/`Mods
// @description    Makes page elements you are using stand out.
// @include       *
// ==/UserScript==
// Edit this script however you want, with all it complexity. =p
//Editing the 1st opacity will set the default and the 2nd will edit ithe hover effect on sections.

GM_addStyle ("*{opacity: .8; } *:hover{opacity: 1; }");