For the weekend of May 21–23, 2010, Google changed the Google logo on its homepage to a fully playable version of Pac-Man. The logo change was done to commemorate the 30th anniversary of the game’s release. This was the first fully interactive special Google logo. Google Pac-Man consumed 4,819,352 hours of time, or $120,483,800 in productivity. The logo is still playable for now at the link below
More @ Google.com/Pacman.