This is an interesting article on obscenity and the court case that overturned the post office's authority to declare books obscene back in 1959. It's particularly relevant to me since I just read Lady Chatterley's Lover last week, and that shit is raunchy.
Most of the books in our house are Mike's, and so I've been randomly working my way through them over the years. Right before my trip to Boston last week I finished A Connecticut Yankee in King Arthur's Court, and so I tossed Lady Chatterley into my bag. I wound up feeling awkward reading it in public places, though - I'm always sure the people next to me on the plane are reading over my shoulder, which in this case would have given them good odds of catching detailed descriptions of nether regions. Or the process of mining coal. Not too different, really.