Received an eMail from the owner of the Metro Card Bike referenced in a prior posting and he pointed me towards this NYT article that I thought you might find interesting: (see June 2007)
NEW YORK REGION June 13, 2008
Big City: The MetroCard Is the Medium, With No Particular Message By SUSAN DOMINUS
A New York City office worker has become a small-scale celebrity on wheels because of his elaborate artistic creations using old Metrocards.
My Flickr set of this years Mermaid Parade is almost finished (still needs some editing & additional uploads) but if you want to see more of his creations point yourselves here:
http://www.flickr.com/photos/patminnyc/2613562504/in/set-72157605792467997/
He has an extensive collection - just follow the links from my photo that he has listed as a favorite....
Enjoy ;-)