Objects & Layers relationships

["Matthew J. Smith" <mas02041 d80h149 public uconn edu>]

Hello all-
  As a Dia user, I just wanted to throw out one of my own observations. 
Currently, an object seems to reside in a single layer, and can have no
interaction (for example, connecting lines) with objects in another
layer.
  I use layers all the time to show/hide the different components of my
drawing.  For example, an IT Environment diagram may have a physical
network layer, a logical routing layer, a server layer, an application
layer, etc.
  It would be very useful to me to have an object that can belong in
multiple layers.  In the above example, it would be great to have the
firewall in all my layers, so that all objects can be connected.  As
well, I'd like to hide all layers except for the one I am interested in,
and still have the firewall show up.
  I think the easiest solution would be to make layer membership a
multi-value attribute of an object.  A layer view would then abstractly
be a query to find all the objects with the selected layer(s) listed as
an attribute.  This would also allow all objects to connect with all
others, regardless of layer, since all objects could belong to some
common "primary" layer.
  Would this type of functionality be useful to anyone else?  Or, should
I just re-evaluate my use of layers in diagrams?
Thanks all,
-Matt