Definitelty, I think it's worth your while downloading and studying the Discus bulletin board system and looking at how they've done it. Basically, each phrase used ANYWHERE is referenced by a var to a language conf file. They even cover issues where a phrase requires two tenses in one language, but only one in another. I was very impressed.

cLive ;-)

PS - in fact, the whole of their source is worth looking at for style gems, if you have the time.