Google's Friend Connect just got a really neat new feature: comment translation. It can now unify the language of any comment thread, turning any and all comments into one language. This means that if you have one post in Mandarin, another in Spanish, and yet another in Russian, you can click an option to read them all in the same language.
Google is using its own Translate API to do the dirty work, which means whatever unintentionally bad translations it would do on the Translate site will happen on comment threads. Friend Connect users who already have the tool installed on their blogs or sites do not have to upgrade; Google is pushing out the new features with the same bit of code.
Here's a quick video on how it works: