The trick is to create a message-array for each supported language. When messages come in, they are added to the array for their own language, and we fire off async https requests to google-translate-api which populate the other arrays when the response comes back.
http://localhost:1337?name=Matthew&lang=en&msg=Hello+World
then
http://localhost:1337?lang=es http://localhost:1337?lang=fr http://localhost:1337?lang=ja
should give you the idea.
Supports en, es, fr, ja at the moment. Full list of supported languages is at http://code.google.com/apis/language/translate/v2/using_rest.html#language-params, you just have to add any that you want to the array at the top.