On Google.com, there is a special logo for Martin Luther King, Jr. today for the official holiday celebrated for his life.
Google's Doodle, as always, works in Martin Luther King's face into the Google logo with nice colors and an glowing pride.
Here is this year's Google logo for Martin Luther King day:

Google has had a Martin Luther King logo for the past several years and we've documented most from today and through:
2012:

2011:

2010:

2009:

2008:

Bing has a theme up today for the day:

Sp does Dogpile but not Yahoo:

Forum discussion at Google Web Search Help.

Comments:
Barbara
01/21/2013 05:19 pm
Love all the previous doodles but this years just doesnt look right. Colors are nice but MLK's face looks bugged eyed and angry.
005
01/22/2013 01:52 am
HAHA Wow after all that man stood for his head is turned into a Google O? Bravo graphic designer you got paid for that?