like_everywhere.user.js

// ==UserScript==
// @name           LikeLoudlyEveryWhere
// @namespace      http://polog.com/
// @include        http://*
// @include        https://*
// ==/UserScript==

(function (){
    if(unsafeWindow.self != unsafeWindow.top){
        return;
    }
    var wrapper = document.createElement('div');
    wrapper.style.cssText = 'position: fixed; top: 50%; left: 50%; width:200px; margin-right: -50px; -moz-transform: scale(8.0)';
    wrapper.innerHTML = '<iframe src="http://www.facebook.com/plugins/like.php?href=' + encodeURI(location.href) + '&amp;layout=standard&amp;show_faces=true&amp;width=200&amp;action=like&amp;colorscheme=light&amp;height=80" scrolling="no" frameborder="0" style="border:none; overflow:hidden; width:200px; height:80px;" allowTransparency="true"></iframe>';
    document.body.appendChild(wrapper);
})();