Philip McCarthy‘s Pareidoloop overlays semitransparent polygons until a human face is found. (github link) It’s inspired by Roger Alsing‘s Evolution of Mona Lisa, where he applied the same technique recreate the Mona Lisa.
(google code link)

A more interesting variation of this technique would be throw the images through a classifier trained to recognize various religious images, print them on toast, and the post the toast to eBay Virgin Mary toast style.