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.