App-TimeTracker, Metaprogramming & Method Modifiers
I recently rewrote App::TimeTracker (new version 2.009 recently uploaded to CPAN). App::TimeTracker now allows you to keep track of the time you spent on various jobs and projects using a simple command line interface.
Customization (eg talking to RT, posting to IRC) is implemented via some nifty (or crazy) meta programming tricks and lots of before/after Moose goodness.
I'll show you the tool and some of the (mostly Moose) features that helped making it possible.
Oh, and maybe you also want to use it to track the time you spend hacking!