If you visit Google today, you will see a hologram version of the Google logo. Here is a picture of the logo:
Why the hologram? Well, today is Dennis Gabor's 110th birthday. Dennis Gabor invented holography 1947. He was a Hungarian-British physicist who received the Nobel Prize in Physics in 1971. He actually has a very interesting history, so read about it at Wikipedia.
Forum discussion at Google Blogoscoped Forums and Google Web Search Help.