Making Perl Reusable with Modules
Perl programs are easy to write, especially if they solve simple problems. If you find yourself re-using the same programs (or worse, the same code), it's time to bundle your code into pieces easier to reuse. It's time to turn programs into modules. Andy Sylvester walks through the three steps of making a simple, standalone Perl program into a robust, tested, distributable, and reusable piece of code.
Link: http://www.perl.com/pub/a/2007/08/09/making-perl-modules.html?CMP=OTC-BD0016219291&ATT=Making+Perl+Reusable+with+Modules