From the vi text editor, see which tests cover the file you're working on, or which modules are covered by the test you're in.
Features on the way: Being able to know which tests cover a particular line of a file!
http://search.cpan.org/dist/Devel-CoverX-Covered/lib/Devel/CoverX/Covered.pm
A piggy bank of commands, fixes, succinct reviews, some mini articles and technical opinions from a (mostly) Perl developer.