I use D.H. Lawrence's (I think it was him anyway) definition of porn -- a creative work that encourages masturbation. I think masturbation is a wonderful thing. So I don't think pornography in and of itself is bad.

On the other hand, taking an image that's obviously wank material and claiming that it isn't because it's "art" is really really silly. mostly because things CAN be both art and porn at the same time, one doesn't preclude the other, imho. Sex is a part of life, so art should be able to reflect that. And good "artful" writing, drawing, photography, wbatever just makes the porn hotter!!