I think ya'll are forgetting one key difference between erotica and porn. That is the degree of explicitness. Both erotica and porn tittilate the viewer/reader. However, porn is much more graphic in it's depiction of what's going on. Porn 'shows' more. Erotica 'suggests.' I do agree that it's often very subjective, but I suspect that few individuals would consider a full on close-up of intercourse or some other sexual activity involving genitalia as anything other than pornography. That's where the line is clearest between the two IMHO. The September Morn image's history would suggest that that line is relative to the cultural norms as opposed to a univeral absolute. Please bear in mind that my intent in that statement is to classify the imagery 'academically' rather than put a moral value judgement on it. For the record, I also believe that something can be classified as pornographic and still be 'art.' Once upon a time back in my youth I came across a porn director named Andrew Blake who's work was clearly art as well as pornography. He took great care with lighting, environment, costuming, storyline, music and all aspects of the final movie to create something that was beautiful. His work was clearly a very different thing from the cheap, "let's rent a hotel room and throw two people in there that are just boffing each other" crap that seems to dominate the porn industry.

Before they made me they broke the mold!
http://home.roadrunner.com/~kflach/