Unlike MySpace, which expanded outside the English-speaking world by launching local offices and versions of its site, Facebook built translation tools that allow users to personalize the existing site in their native tongue. This approach gave it an early presence in foreign markets that grew exponentially as users encouraged friends to join the site. Facebook, which had been translated into 20 languages including French, Spanish, and Mandarin, has recently added 69 more.
Let's just hope that their translation engine isn't based on the same technology recently used by this fast food joint in China:

[Via BusinessWeek and AdFreak.com]