The Pac-Man Dossier is the source for an incredible wealth of technical information on Pac-Man. It covers the history of the game, technical details of how the movement of the ghosts are determined, and why certain areas can be exploited and a ton more. Really worth a quick check through, or a more though reading if you have a chance.
I love these in depth looks at games, and finding out the nuts and bolts of what makes them tick.
(Found on Offworld)