" Organizations which design systems are constrained to produce designs which are copies of the communication structures of these organizations. "
I like to extend Conway's law to talk not just about communication structures, but also about human need.
On Artima : Human-Oriented Architecture
And goes on to talk about the right granularity (always a good word for me) of components in software.
NB : Artima is getting to be a religion for me nowadays. It's just solid with interviews with major *thinkers* about programming and software design, describing their experience and ideas. A fantastic site.