information on tessellation shaders

I would like to start working with the two new shaders in OpenGL 4.0, tessellation control and evaluation shaders, but I have been having a hard time finding any information on them outside of the spec. Can someone point me to something? A tutorial or example would be fantastic. Thanks in advance.

A google search gave me these
http://prideout.net/blog/?p=48
http://codeflow.org/entries/2010/nov/07/opengl-4-tessellation/