use this as the url for a bookmarklet:

javascript:var%20script=document.createElement('script');script.type='text/javascript';script.charset='UTF-8';script.src='http://profil.fesch.at/stuff/console.js';document.getElementsByTagName('body')[0].appendChild(script)

then go to script.aculo.us or any other site that loads in prototype 1.5 + builder.
then, hit "ESC".