Fark linked up this space.com article that has some pictures of old Mars landers. Using a technique to help spot the newest landers, they've managed to image both Viking 1 and Mars Pathfinder. Which proves they weren't actually cannibalized for parts by enterprising Martians I guess. However, since the images are still very grainy, I suppose there still could be "L33t Marz HaXoRz OWNED joo!!" spray painted on them somewhere.