Metroid Prime Hunters (the new first-person shooter for the Nintendo DS based on the Metroid series) features 90 degrees of a pie menu!
Players can select between the primary weapon, a missile launcher, and an alternate weapon. The alternate weapons are acquired from the various other hunters players battle throughout the game. To select among the alternate weapons, the player touches the stylus in the upper-right corner of the screen, then drags in the direction of their weapon of choice, and releases when the appropriate weapon is selected. This is one quarter of a pie menu (since it originates from the upper-right corner). Nicely done!
I’ll get a screenshot of it up here as soon as I can find one.