Automated tests with Arduino

I have been very happy with the Arduino concept. It is a very powerful board with many different adaptations.
The Digital I/O and serial ports have so much potential.

As a former Automated Testing guy with Civil Service Army, I have been intrigued with the the idea of using the Arduino board as Automated Test Equipment to test other boards. Such concepts as Built in self test, Self test alarms that indicate in what step a board fails initialization, and HP Boundary testing were ways of functional testing in circuit, without removing components.

HP Boundary testing was implemented to include test pins on an IC that were not used functionally only during confidence testing.

Thanks for all the resources and ideas.