The Google homepage today has Google doodle balls bouncing all over the place with another interactive doodle launched on Tuesday, September 7.

 Moving your mouse over the four dots or balls that sit to the right of the Google logo will get red, blue, green and yellow balls bouncing all over the page

Source: http://www.examiner.com/google-trends-in-national/the-google-doodle-balls-are-bouncing-on-google-home-page