Bah you anti-photoshop puritans. If you don't want to see an altered reality, the only way is to go outside and see for yourself. If you look at photos on the internet, you are going to have to accept that there is some distortion: the camera that took the image already gives a different image than what your eye sees, since humans simply do not have ccd's in their eye sockets. Then, depending on the monitor you display it on you get another round of distortion from the true colors and brightnesses that your eye would have experienced.
Digital cameras are particularly notorious for their low dynamic range. If there are many different levels of brightness in a scene, your eye picks them all up just fine, but your camera will truncate quite heavily above and below. I'm often quite dissapointed when I come home and see the pictures the first time on my screen: "that's not what it looked like at all!". So the pure camera image is actually quite terrible at representing the actual scene. Only accepting those versions since they are 'not-photoshopped' is just selecting one particular
(inaccurate) digital representation of a scene over another. Using photoshop to bring out the colors and various brightness levels can in many cases actually make the photo more realistic.
So I propose the opposite. We no longer accept pictures from crappy cameras which have not been enhanced by photoshop, since they do not give an accurate representation of reality
In all seriousness, there's nothing wrong in playing with photoshop to get the picture to look a little better. Take the picture Josh quoted, it looks beautiful, it was undoubtely a beautiful scene and I can really feel the atmosphere. It's a good photo. But sometimes it can be overdone, look too colorful, too much messed with, etc. (like the one quoted immediately afterwards, in my opinion), and you don't like it, well in this case you simply vote it down (or if there are animals which have been photoshopped in, argh).