I have some extra vintage photos that were printed on card stock. I don't know much about the history of them. I obtained them in 2007 when I bought out a few collections. I would prefer to sell, but would be willing to trade. Some of them have a facsimile autograph on them, some don't.

The scans can be found here: http://s166.photobucket.com/albums/u111/billyball_2007/Baseball%20Photos/

Here's a list (all approximately 3-1/2 by 5-1/2):
Ron Santo #1 -- Chicago Cubs (my estimated value is between $5.00 to $10.00)
Ron Santo #2 -- Chicago Cubs (same as above)
Ray Herbert -- ChiSox, stats printed on back
Camilo Pascual -- Twins
Lee Thomas -- LA Angels
Wally Moon -- LA Dodgers, stats printed on back

And lastly, I also have a 2002 Upper Deck Mark McGwire (3-1/2 x 5)
[color=#FF0000]EDIT: This card was only given to hobby shop owners and is considered "rare." (My estimated value is between $5.00 to $7.00)[/color]

I'll be editing this post from time to time as I find more info on the above items.

EDIT: I've checked and all the guys in the vintage photos sign, with the possible exception of Mr. Pascual. He has been RTSing lately with a note that he is currently working outside the US. There have been a few successes with McGwire also, but he seems rather hit-or-miss.