I know this is already at the top, via sticky, but maybe a swing into the active list can bring some more sites out of the shadows. These types of sites are great for viewing, but also for reference and information, especially if what you collect crosses over into one of these collections. Variations, set identifications, errors, etc. It's all great information.
Now I just need to stumble upon the ultimate Dodger photo and postcard identification site! I have lots of 8x10s (color photo on card stock), 5x7s (photo packs) and postcards issued throughout the 50s-80s with multiple player variations presumed to be issued in different years, but so hard to tell!