Yes, the code is:
a href="
http://www.youtube.com/v/T4y0OLPelMI&rel=1&autoplay=1" rel="shadowbox;width=640;height=480;player=swf"
and the code to run the shadowbox is:
<script type="text/javascript" src="shadowbox.js"></script>
<script type="text/javascript">
Shadowbox.init({
language: 'en',
players: ['img', 'html', 'iframe', 'qt', 'wmp', 'swf', 'flv']
});
</script>
Cheers!