I used Duolingo for a few hours on its first day. (I used to TA for Luis, which helps for getting private invites, at least by knowing to sign up immediately.)

I've basically just gone through passing out of German lessons. This basically consists of taking a 20 question test, in which I translate sentences like "The woman drinks with her cat." and pray I don't make typos on three questions and have to start over. Except that all too often I give correct translations, but their checker isn't attuned to the flexibilities of German word ordering, or I use a different word for "chair." They said they'd teach it the distinction between "essen" ("to eat" for humans) and "fressen" ("to eat" for animals) so that their quizzes would stop recommending wrong answers, but I'm skeptical. I did another one just now, and it now seems to accept answers off by one character. I noticed this in a listening exercise not because I made a typo, but because the word for "is" is approximately homonymous with the word for "eats."

Oh, apparently Duolingo has something to do with translating the web, rather than just going through a bunch of German 1-level exercises. Maybe I have to repeat the above for the remaining 45 lessons before I see an option to do that.