Hi Jon, I'm glad the automatic UV mapping is useful for you!

It is an area that I want to improve in the future for joined together solids, right now all surfaces of a solids overlap over the base full UV unit square, in the future I'd like to make them occupy separate "islands" rather than overlapping.

Some people use a separate UV mapping utility to solve that problem currently, some choices for that are:
UVMapper: http://www.uvmapper.com/
Unwrap3D: http://www.unwrap3d.com/u3d/index.aspx
Unfold3D: http://www.polygonal-design.fr/

- Michael