I recently became aware of a Web 2.0 site for teachers. It's called Claco and it's a website that allows teachers to share and explore different lesson plans that align with the Common Core curriculum. From my understanding, it seems like a bit of a mixture between Facebook and Pinterest. Teachers are able to create "binders" for their different classes/subjects that they teach. They are able to put lessons found on Claco into their binders so they are able to easily refer to them and implement them into their own classroom. To become a member of the site, you must be invited. I requested an invite and hope to learn more about it soon! In the meantime, check out these videos I found which describes some of the features of Calco.
This is a video from the creator of Claco. He describes basically what Claco is and why this website came to be.
This is a video made by a Claco user. He is describing a basic how-to get started with the site.