Hi Bob,
The notion of modeling from a fixed point of view is contrary to the way humans build things in the real world.
Watch any craftsman at work and you’ll notice they move about, rather than stand in one place with head still and eyes fixed.
Watch any experienced modeler at work in SU and you’ll observe the same; their camera is rarely still for long.
Navigation in SU quickly becomes as natural and effortless as looking across the room.
That ability to freely move about while modeling is what sets SketchUp apart and above the rest.
In fact, the SU modeling environment relates to human nature so well that there’s an interesting phenomenon which occurs to many users after a long modeling session.
That is we’re known to become so acclimated to working in SU’s real-time 3D environment that we instinctively attempt orbiting to get a better look at things in other applications.
It’s then you realize just how cumbersome and un-real other applications really are.
-Geo