I think that one thing this discussion has shown is that definitions of pornography based on content/subject fail. It becomes like the silly situation with Indian cinema posters, where if there is 0.05" separation between the heroine's and hero's lips it's OK and if they actual touch it's taboo. Which brings me back to intent. This is relatively easy if you have access to the creator. So imagine three Poser users, A, B and C. All have produced pictures with sexual content.

Me: Mr A, why did you make this picture?

Mr A: 'Cos I get paid by for making pictures of hot chicks with big melons.

OK, so Mr A's picture is pornography.

Me: Mr B, why did you make this picture?

Mr B: It's a work of art.

Me: Why is it a work of art?

Mr B: Err - it just is. Besides, dphoadley likes it, and it says here that anything that dphoadley likes is art, and anything he doesn't like is trash, and you can't quarrel with that, can you?

Verdict: this is pornography being passed off as art.

Me: Mr C, why did you make this picture?

Mr C: It's a work of art.

Me: Why is it a work of art?

Mr C: Well, I was looking to make something that combined formal beauty with subversiveness; allow me to elaborate on the features of the composition ...

Verdict: Well, this is actually some sort of art, and Mr C knows something about what he's doing. But, as someone asked earlier, is it good art or bad art?

Me: Please can you comment on why is the girl looking so very bored, and why is her hair sticking out at that angle?

Mr C: Err - I didn't know how to fix that.

So - it's art, but it isn't good art. It's technically deficient. It may also not convey either the message intended by the artist or any other message. (Those last four words are important.)