There are a few different iPhone apps out there designed to make inter-language communication an easier proposition, but none of them are quite like the Emirates iLingual app. Combining either French, German or Arabic with those stupid mouth replacement gimmicks you see on late-night TV infomercials, the app lets you "speak" another language through the iPhone.
To use the app, you take a photo of your mouth, which the app will then animate to look like it is talking in the chosen language. As you can see from the YouTube clip above, it works pretty well, although there's one major problem I can see - each of the apps only works translating from English into the other language. How do you understand the response? It's not like you can stick the phone up against their mouth and lip read the response.
Still, the app is free, and you might be able to understand their response if it's in some kind of crude sign language.