I'm really digging Pearltrees, a great way to visualize internet resources in hierarchical organization. You can start with a main idea and then split off into branches of deeper categorization. You can even collaborate with others- this would be a great activity for students who are researching an idea to share resources and then visualize how the ideas they are investigating are related. I've been experimenting with this site through creating a Pearl Tree for IB Film. If you're teaching an IB Film class as well, feel free to help grow the tree!