In English, when we take a picture we try to make people smile. So we ask them to say "Cheese!" because it makes your face look like a smile.
In Spanish speaking countries I've heard people say "whisky!" And in China they say "茄子(qiezi)!" (which means "eggplant").
What about in other languages? I'm especially curious about French, Arabic, and Russian since I'm learning those. But I'd like to hear about others too.
In Spain we say "patata" which means potato 
In catalan we tell "Lluis" a person name, "Louis" in english.
Oh wow. That one definitely wins the competition so far.
FORMAGGIO!! hahha no, actually the italians say "cheese" too. Italians didn't bother to change it. Some people might say "CESSO" which means toilet... I never understood this thing of trying to make people smile. Man, if you have to try to make people smile when taking a pictre, then maybe...they don't really want you to take a picture of them??! hahhaha
Here in Germany you often say "Ameisenscheiße", what actually means "Shit from an ant" but we also say cheese ;)
