Ned Batchelder noted something I found really interesting – that Spore Creature Creator uses Steganography. The super-succinct summary is that with this nifty trick, when you export a PNG of one of your creatures and give that to someone else, they can load the PNG into the creator program and it pulls out structured data encoded into the least significant bytes of the PNG file and you’ve got yourself a creature! Not just the image, but the whole structural component to fiddle with. Sort of capturing the essence of the creature with a picture!
Editing the picture in any way destroys the integral data – and Ned has a great writeup of his investigation on how the Spore guys managed to wrangle this nifty feat.