We are now on Facebook
That is correct, the Cowen-Tabarrok text, Modern Principles. It is a steady stream of resources for using the text, and learning and teaching economics more generally, updated on a very regular basis, organized using the wonders of Facebook.
Don't forget to click the "Like" button.
http://www.facebook.com/ModernPrinciples
Thank you Mark Zuckerberg! I rooted for you in the movie too.