Pictures are subject to changes, mostly... can't prove anything.

The only way to prove it would be to have a personal experience with a medium.
Like, what if the person who died was in a room alone with you, then said something seconds before they croaked. Nothing like "I love you," that's too easy to guess. Something like, "Cancel my WoW subscription, errgggghhhh............."
The psychic then tells you these were the last words. Would that be enough?

Also photoshop.

Ghosts are probably not real. If they are real, they are probably some sort of 4 dimensional shadow. Like, how a 3d object makes a 2d shadow and a 2d object makes a 1d shadow.

I used to watch a show called Ghost Hunters on SciFi. They didn't actually look for tiny little things and yell "OMG IT'S A GHOST", they tried to reasonably find ways stuff could be happening without paranormal influence, but on two or three occasions they'd be like "That shit is haunted" when they couldn't explain something. I think the most notable 'proof' they ever got was when they were in a lighthouse or something. One of their members was sitting inside a closed room, only one exit/entrance, on a stool and his camera was on the other side recording everything. Nothing happened for a while, but when he went to the bathroom, the camera recorded the stool sliding across the floor and changing position. Of course, it could have been doctored, but hard to do.

In another episode when they were on a 'haunted' ship, they had set up a camera in one of the 'haunted' bedrooms and they caught the blanket gradually being tugged off the bed by a 'ghost'. Later, though, one of the members noticed that a pillow on the bed suddenly moved between two of the frames, and they figured out how someone had faked the 'falling' blanket by pausing the video, moving it a bit, then resuming play only to pause again, creating a frame-by-frame effect of a ghost moving the sheets. That just shows how a lot of 'proof', even video, of ghosts can be faked.

Does that automatically mean ghosts don't exist? No. I haven't seen concrete proof that they do, but I have seen a few instances of 'ghosts' that can't really be explained, so I'm not going to take on a holier-than-thou mindset and dismiss any potential finding of the supernatural before rationally considering it.

tl;dr: Don't really believe in ghosts, but I'm willing to keep an open mind on the subject of the paranormal.

4 dimensional objects are moving objects. So a 4d object makes a 4d shadow.

4 spatial dimensions, I'm not using time as the 4th dimension here.

If they were 4 dimensional shadows...
Wouldn't they be shifting in abnormal patterns instead of behaving like an "orb of light" as people claim to take photos of?

i kinda believe in them, ive had many weird experiences at my grandmas house. such as err like a steam coming across teh mirror, door opening and closing fast O.O.
but most of the time it is imagination, but im still kinda paranoid bout them.i watch too much ghost hunters
ragdollmaster: the lighthouse one i think there was a ghost ._.and i kinda lol'd at the cover prank thing

I can only talk from my own experience, and I have experienced feeling watch or feeling an unnerving presence alot. Especially in my old apartment, it was horrible there. Especially in the kitchen.

Woah shit dude. I jizzed.

Woah shit dude, nice post. Seriously, I only warned you this time - but don't keep it up. ~Dalir