PHP kôd:
var videos = ['o-hC-IkFdZw', 'tt8d3Shlfrg', 'aGSKrC7dGcY', '2YQy368xZF4'];
var video = videos[Math.floor(Math.random() * videos.length)];
document.write('<iframe width="560" height="315" src="http://www.youtube.com/embed/' + video + '" frameborder="0" allowfullscreen></iframe>');
http://jsfiddle.net/z7awk/1/