Dutch West Internet based comedy troupe from NYC. Updated Thursdays with sketch comedy and musical (and sometimes political) "white box sessions". They also do a live show downtown the first and third Saturday of the month. Their Myspace has showtimes listed. Got tipped off to these guys after catching their live show by chance and I've been following them ever since.
Look up more - Improv Everywhere has been mentioned before but this latest mission is the largest yet. After reading about it here, I wonder how many people signed up for the NYC list? Were there any other MeFites there? I was window 39...