use Getopt::Long qw(:config no_ignore_case bundling); #or some variation of this.
use Cwd; # I like to keep track of where I started before cd'ing
use File::Basename qw(fileparse); 
use File::stat;
use File::Find; #love this guy 
use Time::gmtime; #for timestamps, etc
use Time::Local; #time's easy to manip if it's a single scalar
use File::Copy; #somewhat DOS/Linux portable (crippled) copy 
use Carp;
use constant CONSTANTNAME => Value; # der...
use Tie::IxHash; #it's slow, but sometimes you need an ordered hash
use File::Compare; #somewhat portable file diff, truthfully laziness usually wins and I usually just call diff as a system call...