I'm trying to get in my head what the rules about assignment are.  So far
here's what I think I've got:

1)  Assignment (=) from a string or number object (the right side) causes
the value to be copied, not a pointer to the object given.

2)  Assignment (=) from any other sort of object (the right side) causes the
object to be pointed to, giving the object another reference.

3)  You use .clone to copy an object's contents to a whole new object.

Is that right?  The only thing I can't figure out is how do create a
reference to a string or number object.

    Sean