HippoCampus has been around for a while. I’d heard about it many times, but it just came back onto my radar. Wow. I’m going to have to go back and put more stuff in my lesson plans for next year! There’s a lot to see here: videos, simulations, interactive lessons. They cover Math, Science, Social Studies and English for Middle School and High School. Teachers can sign up for a free account and organize the content they want to use. All for free.