An all-too-common occurrance managing perly projects is being unable
to install new modules becuse "it might break things", and being
unable to test them because you can't install them. The usual outcome
of this is a collection of hard-coded
use lib qw( /usr/local/projectX ... )
code at the top of each #! file that has to be updated by hand for
each new project.
To get away from this you'll often see relative paths for the lib's,
which require running the code from one specific place. All this
does is push the hard-coding into cron, shell wrappers, and begin
blocks.
With FindBin::libs you need suffer no more.