Wayne State University in Detroit has lots of hi-res photos that were donated by the Detroit News. Just search for New York (assuming you're a Yankee fan) and a bunch of Yankees stuff comes up. You could probably have good prints made from them; they're large photos. There's a lot of old baseball.
http://dlxs.lib.wayne.edu/cgi/i/imag...vmc;page=index
Stuff like this: