Lots of true and probably untrue things being said, I believe that the use of a photo camera makes photography unique.....
First of all, I think photography is a skill. You have to learn it, and some people never will really. Everyone can draw a portrait. Everyone can make a photo. The first by moving a pencil or brush, the second by clicking a button. Is drawing or painting an art? Yes, sometimes. But first of all, it's a skill, as would be most obvious if you see one of my drawings
. It's a skill I don't have. The same holds for photography: it's a skill, but pushing a button isn't as hard as the eye-hand coordination needed for drawing or painting. So, probably the gap between the skilled and the buttonpushers is a bit more difficult to see.
And then from skill to art. There are many who can paint or draw a portrait, with a acceptable result. That is: I can recognise the person, it's skillfully done. Apart from creating a portrait, there is nothing creative in these portraits though..... Only the very gifted make drawings to call art...... Or they add something new, something creative, that makes us say it's art.... I think this is the same with photography. The skills are hard to learn, but they can be learned. For making it art, there is creativity needed. In subject - hasn't everything been depicted yet? - in technique, in material, in PP......
What I am trying to say is: art has to do with creativity, with the search for new expression forms. I am happy when I reach the level of the skilled eventually.
And this is the same as RioRico has put in other words above, I think.....
EDIT: oh, and I believe art has to do with interpretation as well..... It's ones interpretation of reality, not a mere report of reality. Having said that, I often can give a certain interpretation to my photos, but that is not the point of what I meant. It's rare to find myself in a situation where I want to make a certain photo as an interpretation of reality - so before I release the shutter.... It's not THAT hard afterwards....but a priori......