// ==UserScript==
// @name           Paul Blair's Mowser Images Script
// @namespace      superkeen.com
// @include        http://www.howtocreate.co.uk/tutorials/javascript/operators
// ==/UserScript==

var pics = document.getElementsByTagName("img");

for ( var i = 0, pic; pic = pics[i]; i++ ) {
        pic.src = "http://mowser.com/img?url=" + pic.src;
}