I just used the demo pictures that were in the demo version of GreenscreenWizard (http://www.greenscreenwizard.com), and ones found with a google image search ('chroma key green') like the one on this page: http://store02.prostores.com/servlet/tu ... een/Detail
I just purchased a piece of green cloth so I haven't had a chance to take any of my own yet.
-Tim