Today is one of my favorite holidays, Pi Day. Yes, today is March (3), 14th and Pi is 3.1415926. This year, unlike last, Google has a logo. Here is the special Google Doodle for Pi Day:

Bing, Yahoo, and the other search engines don’t seem to have a logo for the day. We took the time to change our complete theme for the day, here is a picture:

I should note, that although Google did not have a logo last year, they did mention it in a blog post and they did tweet it.

DogPile also has a special message on their web site, but they reserved it for the clock change. Here is their spring forward logo:

Forum discussion at Search Engine Roundtable Forums & Google Web Search Help.

Update: As per the comments, it is also Mother’s Day in the UK with the following logo at google.co.uk:

And the anniversary of Félix Rodríguez de la Fuente, which is represented at google.es today: