The Methods & Tools newsletter has just released in its html archive
section the article "Responsibility Driven Design with Mock Objects"
by Marc Evers and Rob Westgeest. Responsibility driven design is an
approach that helps you shift focus from object state to interactions
and responsibilities. This article shows how test driven development
with mock objects facilitates responsibility driven design and drives
you towards a more cohesive, loosely coupled design. Examples in Java.
http://www.methodsandtools.com/archive/archive.php?id=90