Is there a hardware test routine out there for an Arduino

After reading http://ruggedcircuits.com/html/ancp01.html

and considering my projects (Long use, High voltage, non-standard wiring, mould growing on the PCB and so on) I want to find or create a program just to check if all my pins are responding, timing is ok,and whatever other considerations i can check to reassure myself that my old workhorses are still reliable.

Its not that I am cheap, I have three already, but I like to know if I am breaking my OWN programs, or if one pin out of 19 is just a little fried. I tend to use the materials at hand rather than buying a new setup to try a little idea

Can anyone recommend a sketch already out there, or advise what parameters I can check aside from a for(pins){blink} Cycle?

Maybe look here: http://arduino.cc/forum/index.php/topic,50203.0.html ?