Looks like Flick Software has made a program that successfully emulates the iPhone's patented "MultiTouch".
For those curious, even devices like the HTC Touch line (including the Diamond) all use resistive touch screens i.e. less cool than capacitive like in the iPhone.
The two programs, iSwish and iZoom, are still in testing and unfortunately looks like Flick Soft's website is down: www.flicksoftware.com
We'll keep you posted on any new info.