Well, actually it is not that simple to do very quickly if you don't do this for a living.
However, yesterday I found this excellent site and it is free if you print your own.
http://www.epassportphoto.com/" onclick="window.open(this.href);return false;
Just take a head and shoulders shot and upload it, the site lets you resize/frame it exactly to meet the passport regulations and then lets you download it sized for a 6x4 print of multiple photos all ready to cut up. Dead easy and quick. Saves an awful lot of time.