Geeklet pulls photo of the day from National Geographic website and saves two copies in Pictures directory: latestNatGeo.jpg & latestNatGeo_flip.jpg.
Just use two picture geeklets to display the images and reduce the opacity of the flipped image. Ticking the shadow option for the main image makes it look better too.
The horizontal system meters are inspired by IvyLeaf's clever scripts. The ocean wallpaper is included in Lion.