The official London Olympics education site. You can register and join their blogging network. This is definitely something you may want to do with your students.
The London games has a "get set" website which is their official educational platform for the Olympic games. I've just spent a little time looking at what you can do there, but you can register, blog about the games, and connect with others. This is the sort of global event where you can meet other classrooms and interact with others.
IF you are a foreign language teacher, you should take a look at this lovely wiki where teachers are sharing stories and students and teachers are writing them. Language is a perfect place to flatten the classroom.
"Hi! And welcome to the Wikispace where you can share and enjoy stories written by and for teachers and learners of French, German, Spanish and Italian. At the last count, we had 86 Storybird creations, contributed by 30 different authors in 4 different languages."