In a decidedly Facebook-style move, Twitter is asking for its users' help in translating the service into new languages. To start, Twitter is focusing on translating the site into French, Italian, German, and Spanish.
Twitter is starting with a small set of translators, but if you want to sign up to translate the service to the language of your expertise, you can enter your information here. They're looking for translators for just about every language from Finnish to Thai. As translations of the site are completed, Twitter also plans to offer up the translation files to the developer community to help translate their apps for Twitter's new markets.
Twitter translators get a special badge on their profile and are given levels (1-10) based on how much translation they have done. Twitter has also built leaderboards for each language being translated. You can see the one for the French translation here. This gives the translators a little more incentive above just knowing that they have contributed.
At the beginning of 2008, Facebook started a similar user translation effort, which has been a huge factor in the site's international growth. Recently, Facebook also introduced a translation tool that works with Facebook Connect and allows site owners to have their site translated by Facebook users. Twitter is hoping that expanding into new markets through these translations will blow up their user base, just like it did for Facebook.