You'll have to be quick - these things only stay up for about 24 hours. But today, January 11, Google is honoring the birthday of Nicholas Steno, the "Father of Stratigraphy" and much more to the science of geology. Check it out at: www.google.com.
Just click on the "stratified" word that says Google. (In case you are too late to see it, I have added a photot of my desktop with the entry page for Google on January 11, 2012.
And Happy Birthday Nicco!