Check out... old vintage French post cards at
http://ly.lygo.com/ly/wired/news/images/full/rr-1920to1939_f.jpg
from an article at
http://www.wired.com/news/culture/0,1284,68790,00.html
Photos taken between 1920 and 1939. WAY BEFORE PLAYBOY MAGAZINE.
Actually photographic porn exists clear back to the middle of the 19th century...to the very beginnings of photography. Before that, there were paintings, engravings, etchings and other depictions of erotic images.
There's even pornography at Pompeii, and that dates back a long, long way.
Whatever medium is available will have its pornographic subjects. Thus has it always been, and thus it will always be.
Pornography drove the internet to success by being one of the first money-making ventures on the web. No sooner does a new technology appear than the demand for porn using that technology appears.
Hefner published a magazine that contained photos of nude women, airbrushed to remove every blemish. Before that, you had to go into some greasy room in an auto shop to look at images of naked women on the calendars hung there.
Men like naked women, and that's a good thing. Without that attraction, none of us would be here.
That's funny. The French postcard you linked to shows two women. I guess the whole girl on girl thing is nothing new. [grin]