Hardware Pacers has the Microsoft Wireless Optical Desktop Pro tilt. Looks
like a nice combo, check out here
what they think.
Tilt Wheel Technology: Experience unrivaled accuracy, speed, and control-new
wheel functionality and intuitive software enables enhanced, accelerated scrolling
through documents and Web pages. Depress the wheel to toggle between open windows,
making multi-tasking a snap. Your screen will move as smoothly as the scroll
wheel feels .