Over the years it has become a regular occurrance and a team of designers has been busy designing over 300 designs for google.com in the US and over 700 internationally.
Some of the designs have been very unique, like the playable Pacman game to celebrate the anniversary of Pacman. But today's is the best I've seen. Today's Google Doodle commemorates Les Paul's birthday. It's a playable guitar that lets you record for 30 seconds and leaves you a unique link so you can keep your recording. Though, for some reason everything you play on it sounds like crappy indie hipster music. (see True Story...)
Here's mine: http://goo.gl/doodle/17Uz ...move over Death Cab for Cutie.