On many Google home pages, with the exception of Google.com in the USA and many other countries, you will see a logo for Shakuntala Devi.
At first the logo looks somewhat like a ticking time bomb, but in reality, it is to show off Shakuntala Devi awesome human computing powers.
This logo specifically depicts her 1982 Guinness Book of Records where she demonstrated the multiplication of two 13-digit numbers 7,686,369,774,870 × 2,465,099,745,779 picked at random by the Computer Department of Imperial College, London. She correctly answered 18,947,668,177,995,426,462,773,730 in 28 seconds.
Devi was born on November 4, 1929 in Bangalore, India and passed on April 21, 2013 at the age of 83. For more on her life see Wikipedia.
This is all while, yesterday was the Diwali holiday in India and Google India did not have a logo for the special day.
Forum discussion at John Mueller Google+ and Google India Google+ and Google Web Search Help.
Update: This logo is now live on Google.com USA.
