I have a hunch
Hunch.com is a new site that has nothing to do with teaching English at first sight. Come to think of it, not even at second sight. But if you're an English teacher, you look at websites from a different angle - you tend to somewhat disregard their original purpose and try to come up with ways of using them in your teaching. With Hunch.com, this is fairly easy, since it is a typical Web 2.0 site and so it is about you, the user - just like a good language learning activity should be about the learner. Hunch.com helps with decisions the social web way, using the collective knowledge of their user base. After establishing your preferences, you can get answers to questions like "What's the best dog breed for me?", "Which URL shortening service should I use?", or "Which cheese would I enjoy?" Your students will be eager to compare their results and will most probably suggest questions to each other - a truly communicative activity; the format you set for this is up to you. Of course, site users can also add their own questions and start new topics - an excellent way to improve writing skills, needless to say.