Asus Eee PC 1101HA - Manual (Page 19)

ASUS Eee PC 1-11
Zoom in
Zoom out
Touchpad Usage
Multi-finger gesture input
Finger gesture Applications
Two-finger zooming in/out Impress, Adobe reader, Photomanager
Two-finger zooming in/out - Moving two fingertips apart or together on
the touchpad to zoom in or zoom out. This is convenient when viewing
photos or reading documents.