How to Win at Pac-Man

Pac-Man is a game of patterns: the ghosts move in predefined patterns, so if you move Pac-Man himself in one of three (fairly complex) patterns, it's possible to avoid the ghosts and play the game almost indefinitely -- at least until you hit the Level 256 "kill screen".  This video explains the relevant patterns:

More on this and links to an article on how to beat Ms Pac-Man at Mental Floss.