I just read about Duolingo on CNN. The concept is fascinating: teach people foreign languages for free, by feeding them text to learn and/or translate, some of which comes from real websites. In the end, you end up translating the entire web—the real goal. Some of the gotchas are obvious: getting enough participation to succeed on such a large scale, for example. Others are less obvious: e.g., how to get enough help translating text in truly obscure languages (those with a few million speakers or less). Still others are very obscure: how to translate text that, in many countries, either is illegal to view at all or at least raises potential difficulties for the viewer (for example, translating Wikileaks material or “how to” manuals dealing with explosives may draw attention). In other words, some parts of the web may stay “dark,” at least in some languages. And in any event, non-native translators will be doing the vast majority of the translation.
At the end of the day, I have no idea how well Duolingo will work, but it’s a very interesting concept.