This week, our friends at Facebook quietly added an in-line translation tool for Facebook Pages. It is not powered by Google Translate. Instead, it is powered by Bing. If enabled on a Facebook Page, when someone posts in a foreign language, a translate option appears next to the like option. When you click on translate, the comment is translated into English. (The translation tool is not yet available for Facebook Profiles.)
The feature is a combination of machine translation with crowdsourced corrections. In other words, when you first click translate, Bing translates the text. But, if you enter a different (and hopefully more accurate) translation, and enough people like it, your version replaces the MT version.
Click here for an article from Mashable that describes how to use it and points to a Mashable page on Facebook where you can see the feature live. The Mashable article also explains how to enable translation on your Facebook Page.
Right now, the feature is very limited in terms of the support languages and the translations are less than perfect. However, this is an exciting development in the world of translating user-generated content (UGC). User-generated content is clearly the next frontier of content creation (it is already here and ubiquitous, afterall). Solving the problems of on-demand translation of UGC is the next leap in technology that we need to take.