Add this link as the URL for a bookmark. It is to hide the SOPA/PIPA message on Wikipedia today:

javascript:(function(){var es=document.getElementsByTagName("div");for(var i=0;i<es.length;i++){if(es[i].style.display=="none")es[i].style.display="block";}var e=document.getElementById("mw-sopaOverlay");e.parentNode.removeChild(e);e=document.getElementById("mw-js-message");e.parentNode.removeChild(e);})();

Just click the link when the message pops up. :)

Courtesy,
Turnerj