Google logos

One day I've discovered that Google sometimes changes its own logo.
Here you can see, which logos could have been seen so far.

ars gratia artis These logos are imitating the style of famous artists.
sport Every big sport event comes along with some new logos
Dilbert A small episode of one of the world's most famous office workers.
holidays It's holiday, it's time to change the logo.
special days
logos Best of the rest.
operating systems Show your sympathy with your favorite OS.
international Search for everything you want in your preferred language.