Palm Pre Plus - Manual (Page 21)

Chapter 2 : Basics 21
Scroll gestures
Scroll slow: Drag the screen in the desired direction.
Scroll fast: Flick the screen in the desired direction.
Stop scrolling: Tap or drag the screen while scrolling.
Zoom gestures
Zoom in/pinch out to increase the size of items on the screen in Email, Web,
Photos, Doc View, PDF View, and Google Maps: Place two fingers on the
screen and spread them slowly apart.