Deactivated parent with active child

Just watched the tutorial on activating game objects and I came up with a question:

On what situation would I want to set a parent deactivated while keeping one or more of his child(ren) active?

The unity gameObjects work with the child parent relationship if you deactivate parent gameObject the child will also deactivate.

When a parent object is deactivated,
the deactivation also overrides the
activeSelf setting on all its child
objects, so the whole hierarchy from
the parent down is made inactive. Note
that this does not change the value of
the activeSelf property on the child
objects, so they will return to their
original state once the parent is
reactivated.