I made a presentation to Madison.pm on software testing in general and Perl testing in particular. It was intended to be introductory since many Madmongers are casual Perl users and most do not have the testing religion. After discussing reasons for and types of testing, I delved into Test::More, Devel::Cover and Test::Class with some simple examples. Throughout the talk, I emphasized that the primary reason for testing was to gain confidence in a body of code.
(the S5-based slides are optimized for Safari in 1024x768, but should be readable elsewhere)