Our favorite website, Google.com, from time to time replaces its basic logo with one created to celebrate a particular person or event.
Yesterday was artist Alexander Calder's birthday. He's most famously known for inventing mobiles, wire-and-metal clusters of objects that move when touched.
The Google logo for the day moves realistically when you "push" it with your mouse. You'll also notice in the video that the shadow below moves as well. Pretty impressive.
Any geeks reading this may be interested in knowing that the animation was done using HTML5 Canvas and realtime 3D rendering.
Official Google logo page.