Los links for reference for pulling info from Vimeo API with PHP.
http://stackoverflow.com/questions/1361149/get-img-thumbnails-from-vimeo
$imgid = 6271487;
$hash = unserialize(file_get_contents("http://vimeo.com/api/v2/video/$imgid.php"));
echo $hash[0]['thumbnail_medium'];
http://davidsonj.com/blog/getting-thumbnails-using-vimeo-api-php
https://developer.vimeo.com/apis/simple