Ive only seen one real ghost photo, one an English friend's budddy took in the ruins of a WWII USAAF bomber base in Essex. A strange kind of myst, really odd, that was taken in one of the old base buildings. A psychic was consulted and even found a name to associate with it, but that may be just her doing her professional thing.
I've seen enough ghosts that I think there must be real "spirit" photos out there. If you can see it, I think you can probably photograph it. Shame some folks go to so much trouble to fake them. Each ghost I have seen "with my own two eyes" didn't look like dead people. However, the thing in the attic of the house I grew up in I wouldn't wanted to have seen. I never went back up there after that encounter.
Recently, I've been a bit into EVP stuff. I'm sure a lot of it is fake, but some of it is very creepy. You can find some recordings using Google.
Dane