bare necessities?

I mentioned that sometimes I spend a lot of time thinking about, among other bodily things, sex. Sometimes, it's even in a theoretical sense. This week, I've just barely barely barely started reading a book called Times Square Red, Times Square Blue by Samuel R. Delany. I'm reading it for (this is amazing, and makes me like technology a tiny bit more) a queer feminist book group that meets in bars to discuss, which I was invited to join over okcupid, a dating website. This is like my 21-year-old-newbie-feminist-self's wet dream.
Anyway, I've heard of this book before, but I've never managed to get around to reading it. It's basically about public sex culture in New York and how the city's "renovation" of the Times Square area has effectively erased what the jacket describes as "points of contact between people of different classes and races in a public space." Given that I've only read a few pages so far, there already seem to be lots of interesting questions popping into my head, which bodes well for the book. Is public sex necessary? What purpose (for either people or for the dynamics of urban spaces) might public sex interaction fulfil? Is there a difference between the types of interactions that happen in, say, men's restrooms and the interactions that might take place in some sort of safer and more accepted theoretical space? Can such a space be permitted to exist at this point in our society?
If this is good, I might have to go on a little public sex reading binge. Ooh, if I were an academic... I'm envisioning using theory and erotica and mass media sources to form one really awesome paper abstract.