Dr. Weimin Mo posted a link on his website, http://weiminmopaintings.blogspot.com/, to a Stumbleupon site, "Street Art Utopia." The first two are from Lodz, Poland.
http://www.stumbleupon.com/su/324fat/:1FbDHKmNf:PeJZ8zOV/www.streetartutopia.com/?p=10554/

This one is from Manchester and is titled "Truth is coming and cannot be stopped:"

Heh-heh-heh.