2009/1/16 Brian Brian.Mingus@colorado.edu:
I like Sam's point.
Do you really want to print this on a t-shirt?
http://en.wikipedia.org/w/index.php?title=Main_Page&action=history
Also, it makes specific reference to Wikipedia.
Since you would also have to include complete copies of the GFDL and GPL I wouldn't worry overmuch.