Who doesn't know who Pacman is? Come on, every year Cartoon Network airs his Christmas special! It was a massively popular arcade game way back in the 1980s. Since then its had all kinds of updates, now Pacman goes on adventures in expansive 3D worlds like Mario or something, but in the end, the original is still the best.
I used to play this all the time on my old cell phone, constantly trying to beat my previous records. As pacman you're trying to dodge evil ghosts while racking up points by eating these white spheres throughout the maze you're in. Large white spheres make you able to chomp on the ghosts and earn even more points. The object of each stage is to clear all the spheres out of the maze.
Online Pacman is free (these days all cell phone games are only like 30 second trials). Its fun and very addictive and you'll probably find yourself indulging in it at work to kill time. So anyway, check it out and play a game or two, maybe you can make it on the high scores and see how you rank against the massive drones of other players.
One thing I don't like about this one is that it seems to move a lot faster than usual so you need to really think must faster.