This is cool: an MMO devoted to language learning via full immersion.
Zon is an unique interactive massively multiplayer online role playing game for learning Mandarin Chinese.
By interacting in the Zon environment you will be exposed to Chinese language and cultural knowledge in a new and exciting way. Everything that you do in the game is another chance to learn new words, phrases and cultural info about China. Never before has learning Chinese been more fun.
Not at all the first time this has been tried, of course; at SOE we supported a few college campuses that were doing full-immersion language learning via EQ2, for example.