a little Prototype.js magic for returning the domains of external JS files

external_script_domains.js

$A(document.getElementsByTagName('SCRIPT')).reject(function(s){ 
	return !s.getAttribute('src');
}).map(function(s){
	return s.getAttribute('src');
}).reject(function(u){
	return u.charAt(0) == "/";
}).map(function(u){
	return /^https?:\/\/([^/]+)/i.exec(u)[1];
}).uniq();