My school has got you all beat... well, at least they did. There was a point in time where they blocked all search engines, all email services, and all forums. Needless to say, that wasn't a very productive week in the tech lab.
I think Mayfield (my highschool) takes the cake.
They blocked EVERY website. When you wanted to go to the lab you had to submit a list of sites you were going to visit beforehand. Searching for anything must've been ridiculous!