I’ve spent some time working with and presenting on extension methods.  In this screencast I create three different extensions.  One to check if a string is null or empty, a second to release my presentation code from the shackles of System.Console.WriteLine(), and a third that shows how to create your own iterator inside of an extension method.

You can download the file here.  You will also need the Camtasia codec which can be downloaded from here.  As always, I welcome feedback on my style and content.