Culled entirely from the gigposters.com discussion board, please enjoy the following selection of on-line digests, mostly popular-art-related. Or, you know, just go to the source:

Symbols.com
"Explore a World of Symbols: Symbols.com contains more than 1,600 articles about 2,500 Western signs, arranged into 54 groups according to their graphic characteristics."

The Museum of Anti-Alcohol Posters
Soviet anti-alcohol posters. Interestingly enough, there are no sites devoted to Australian anti-alcohol posters.

Hell Bank Notes
An article by BigWhiteGuy about Spirit Money in Hong Kong. I have some of these. I wonder if I should throw them away.

Images of Mathematicians on Postage Stamps
Yes, really.

The Map House Gallery of Antique Engravings
Not of maps. Well, actually I suppose some of them might be.

Ad*Access
"The Ad*Access Project... presents images and database information for over 7,000 advertisements printed in U.S. and Canadian newspapers and magazines between 1911 and 1955."

X-Rated Movie Posters of the 1960s and 1970s
The movies were X-rated - the posters are more PG. I wouldn't open them at work myself, but then I work for prudes.

Crime Boss
Crime Comic Books of the 40s and 50s cover gallery.

Monster Mags
Another gallery of covers.

Super Marketing
Ads from comic books.

Exploded Blueprints of Hand Guns
I'm not sure what use these are unless you have one you're trying to reassemble and can't. Serves you right for taking it apart in the first place, dumbass! Sorry... Mister Dumbass.