// ==UserScript==
// @name	AussiePic
// @include	http://forums.topcoder.com/*
// @include	https://forums.topcoder.com/*
// ==/UserScript==

var as = document.getElementsByTagName("img");
for(n=0;n<as.length;++n) {
    if(as[n].src.indexOf('/i/m/aussie_big2.jpg') >= 0) {
        as[n].src = '/i/m/aussie_big.jpg';
    }
}