You're not allowed to smile! It's official...Australian Passport Renewal Application
"The photos must be taken with a neutral expression (not laughing or frowning) with your mouth closed"
Same in the UK, but not the USA. Is this a Commonwealth thing then, that you can't smile in your passport photo? How long has this been going on for? I'll bet you're allowed to smile in the Axis of Evil (or the Axis of Good!), just not in the Commonwealth!! So in which countries can you smile, and where is smiling banned?
Ah, it looks like we stopped smiling in 2004, to combat terrorism!!