Sophisticated theorists of cultural decline argue that our modern era tolerates behavior formerly relegated to the underground. Unsophisticated theorists of cultural decline believe that no one screwed or snorted anything until around 1967. Members of the latter group may want—for strictly educational reasons, natch—to view the images collected at Porn Evolution, a site devoted to "sex from 1870 till 200X."
Warning: This is an actual porn site, so if you're offended by this sort of thing you might want to skip it, and if you're surfing the Web at work you might want to hold off clicking through until you've gone home. The boss might not be sympathetic when you explain that you're only looking at nekkid wimmin because of your deep interest in cultural history. Then again, your spouse might not take kindly to it, either. Caveat clickor.
[Via The Peculiar One.]