If you use Friendfeed, you probably know about this already.
One of our newest members,
Micah Wittman is probably best known for his great collection of scripts for Friendfeed, but recently he decided to take one incredibly useful one and branch out and support Twitter, Identi.ca, and Facebook, as well.
Translatorize is both a set of Greasemonkey scripts and bookmarklets that uses Google Translate to automatically translate user submitted content on those 3 social networks to your native language. It is capable of translating multiple languages on a single page, as well as on pages that normally wouldn't be accessible to Google Translate (non-public pages), and it can handle real-time content, too.
With these scripts, if everyone on those 3 networks uses them, we will all pretty much understand what each other is posting. I have seen conversations cross the language barrier in ways I have never seen before. Imagine a conversation between someone typing in Chinese, another typing in Persian, and still another in English, and all 3 people understanding each other, in real-time. I have not only seen it, I have been a part of it, and it's awesome!
Yes, there are the usual pitfalls that are involved with using Google Translate, as the translations are not always perfect or meaningful, and sometimes it "translates" things that need no translation, and sometimes the translations can be
quite amusing, but all in all, this is one incredibly useful set of scripts that is likely to open a whole new world of social networking communication.
EDIT 11-24-2009: added mention of Identi.ca.