Look at the large tire track in the lower right hand corner of the top one, and the lack of shadow on the skull. The first skeleton is identical to the second, minus the gun, with a different hole dug around it. In photo number three, no archaeologist in their right mind would be digging in with a shovel like that. In photo number four... Is that guy really going to try to dig into a solid rock face with two shovels? I can't really figure out which parts are shopped together in that one, but there are a few interesting things about it. 1, There appears to be some pixelation around the guy that would indicate that he was added. The lighting on him matches the wall very well though. 2, There are no lines at all defining the edge of the skull, shadows to indicate depth, or cracks that would flatten the skull and eliminate the shadows. 3, The grain of the rock face would appear to match the scale of the live man, but there are some places around the skeleton that appear larger and looser, like they would fall off if the skeleton was actually on a wall like that. I think the actual skeleton is laying down like the others somewhere. Pretty good Photoshop, but it's still fake.
http://www.hoax-slayer.com/giant-skeleton.html Urban Legends Reference Pages: Giant Human Skeleton Found in Saudi Arabia http://www.snopes.com/photos/odd/giantman.asp
Webley Revolver - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Webley_Revolver#Webley_RIC