This is a great place to find top-notch lectures on various topics. I found this when looking up string theory. They have lecture series as well, and frankly, they're really, really cool.
This could be great for all teachers, I think!
It's a great way for English teachers and students to keep track of the books they've read and be able to remember them. It's also a great way to share what books you've read. You can makes groups and have discussions, too.