MagicPrefs is a free menubar application for OSX which aims to improve the functionality and configuration options of the Apple Magic Mouse. It features the ability to bind a variable number of finger clicks, taps, swipes, pinch and other gestures to functions like Middle Click , Hold Down Both Mouse Buttons , Spaces , Expose, Dashboard etc.

Touch Sensitivity implements a single point control for a number of factors impacting the algorithms of the taps, swipes, pinche and other gestures.
Tracking Speed adds the ability to increase the maximum mouse speed by a extra 200%.

Also featured is a real-time display of the fingers touching the surface of the mouse that you can enable to test and monitor the way the mouse sees your input.

Requirements:
OS X 10.7-10.8
Intel

Also available are:
Intel version 2.2.3 for OS X 10.6
Universal Binary version 1.9.2 for OS X 10.5