<i>use the mouse for precise on-screen pointing without getting your hand in the way of what you're doing</i><p>If you're a developer or a similar tech-savvy mind, it should take you all of about 30 seconds to come up with an alternative for precision pointing in multi-touch.  (It would have to be app-specific at first, of course.)<p><i>"but the specter of having a small user base for my experiments always discouraged me."<p>Why does that matter? Not everything is about how many people adopt it. If you can make a small group really happy that counts for something too.</i><p>Depends on the size of the user base, and its composition.  Having a small, unimaginative, not-savvy, highly conservative user base is no picnic.  Been there, done that.