http://mirsky.caltech.edu/~eveander/guess.html
While there are many computer graphics artists who strive for photorealistic images, this page goes in the other direction. Here you will find a small preview image which should be viewed in its enlarged version. Your task, should you take on this mission impossible, is to identify 'What on Earth it is.' To give you some help, users are provided with the guesses others have made. Good luck!