Rule of 3rds - an Agile Agreement Approach

http://adjix.com/wipb

Mule, XML, how to Test Drive Configuration?

How do you test drive this XML?

http://www.mulesource.org/display/MULE2INTRO/Hello+World+Example

or more to the point how do you ensure 100% coverage of your wiring?

Cost of Change - Scott Ambler

http://www.agilemodeling.com/essays/costOfChange.htm

Great diagram demonstrating how pair programming catches problems a lot earlier than traditional system testing and is cheaper in the long run