I just posted this photo in the 'trickery' thread but thought it was pretty simple to explain and would fall under 'photoshop art'. Of course there are always more than one way to do this, it worked, so it's good enough for me. 
Multiple skulls in flying sand.
I've found that HDR really enhances sand texture. I took the dull sand shot and processed a few single image HDR's, one for the sand, one for the sky and one for the car using Dynamic Photo HDR. The sand shot was blended with the original at 80% layer opacity. The car layer mask only allowed certain parts of the car to show then I flattened the image. HDR was really toned down while tone mapping.
I ran the image though Imagenomic Noiseware Pro cranked way up to smooth everything out then pasted that layer on the new blended image. A layer mask allowed to keep the sky and foreground sand smooth along with parts of the car. Gradient fade used on the sand, brush on the sky and car.
Several skulls were placed over the sand, erased the hard edges with a layer mask and slightly blurred with gaussian blur, then each layer property was switched to screen and the layer opacity adjusted. Each skull was moved until it looked right.
Flatten, then one swipe with a huge brush to burn the sky with a slow fade and a little burn in the dark areas of the sand.
I'm using Photoshop 7, I've got CS3, but my laptop won't handle it. Currently no desktop.
