Pie menus are often used in games (examples: The Sims, Monkey Island 3, Full Throttle, Neverwinter Nights) because they only require screen space when activated. As opposed to context menus, they allow very fast access to commonly used actions, as the experienced user is able to immediately execute a certain action by simply moving the mouse in the appropriate direction while pushing the button, and then releasing it. This is similar to the way mouse gestures work, but differs in that the user does not have to consult a manual or rely on trial and error before being able to use the gestures. For applications which are used regularly, mouse gestures may be preferable because of their lower intrusiveness. Optionally, pie menus may be designed in such a fashion that they only pop up when the mouse button has been held down for a certain amount of time, so they operate like mouse gestures when used quickly.
Example for a pie menu taken from the computer game The Sims. The player can choose the options by moving his mouse away from the center into one slice of the "pie".