Thanks for the answers. I'm trying to compare the SpaceNavigator with a mouse with regard to rotating a model. It seems to me that this aspect is the biggest weak point of the SpaceNavigator or Spaceball, so I'm trying to find out exactly how big of a problem this is.
Simon's suggestion is the same as for using the mouse, except that when using the mouse, depending on the delay specified, the rotate point will automatically set itself to whatever the cursor is over when pressing MB2. In this regard, the mouse if faster.
cowski's suggestion does not apply in this case because we are talking about rotating around a detailed part of a larger object, so zooming in and out is not an acceptable solution.
John, I'm still skeptical. Consider a situation where we have a long, thin cylinder and we zoom up close to one end if it. Now we want to rotate around this area. Would this be possible at all with a Spaceball without setting the rotate point first? With a mouse, if the delay is set to zero, you'd simply press MB2 on the part, then you can start rotating immediately without the part disappearing off the screen.
I'm going to have to find a demo to test one out first to understand fully how the SpaceNavigator works.