"Sesamouse": Zoom and rotate with Magic Mouse!
The Magic Mouse hardware is full of potential — so much more than scrolling and swiping. Sesamouse interprets more motions, letting you zoom and rotate in gesture-capable apps like iPhoto and Preview. It even sends information about each finger on the mouse's surface to software that supports advanced multitouch. Just open Sesamouse to open sesame!
http://calftrail.com/sesamouse/