Let me contribute by pollishing up the look of your script (you deserve this):

(just replace your comments and the

use Tk;
[download]

 
 use Getopt::Long;
 use Pod::Usage;

use Tk;

my $VERSION='1.00';

=pod

=head1 NAME

[ TkRollerCoaster.pl ]

=head1 DESCRIPTION

 There was an "advanced perl programming" weekly contest awhile back( 
+now defunct I think".
 One I entered was a roller coaster simulation. The original contest h
+ad various *.rc files
 to make any kind of coaster track design. I just included a nice one 
+in DATA, to make the script self-contained.

 This approach is a very simple method to simulate
 the roller-coaster motion. I didn't waste any time
 on actually computing the velocities or positions,
 rather I relied on the Law of Conservation of Energy,
 which says that the sum of the Kinetic and Potential
 Energies will remain constant. The initial total energy
 is the potential energy at the highest point, and that
 is released into kinetic energy( i.e. velocity) as the
 coaster drops.  So as the coaster drops,
 it's KE increases, and as the coaster climbs it's KE
 decreases, and stalls if it climbs past it's start height.

 I figured this was the best approach, since we don't have
 an actual equation to differentiate to get the instantaneous
 values. So this is not mathematically exact, it ignores the
 constants in favor of better animation.
 After all, it's just a visual simulation,


=head2 OPTIONS AND ARGUMENTS

 (-)-h(elp)       Help: shows these options
 (-)-m(an)        man : shows this pod
 (-)-v(ersion)    print Modules, Perl, OS, Program info

=item B<--version o -v>

 Prints module && script versions

=item B<man>

 Man: shows these options

=item B<help>

 Help: shows this pod

=back

=head1 SYNOPSIS

 Roller Coaster

=head1 SCRIPT CATEGORIES

 fun

=head1 OSNAMES

 any

=head1 AUTHOR

 zentara #http://perlmonks.org/index.pl?node_id=131741# << zentara@zen
+tara.net >> ~  Aug 09, 2005 at 15:03 ART (#482340)~

=cut


my ($opt_help, $opt_man, $opt_versions);

GetOptions(
## EXPECTED GETOPT: ! JUST MENTION THE WORD

  'help!'     => \$opt_help,
  'man!'      => \$opt_man,
  'versions!' => \$opt_versions,
      ) or
      pod2usage(-verbose => 1 ) && exit;  ## EXIT WITH SOME INFO

pod2usage(-verbose => 1)          && exit if defined $opt_help;
pod2usage(-verbose => 2)          && exit if defined $opt_man;

 if(defined $opt_versions)
 {
    print
      "\nModules, Perl, OS, Program info:\n",
      "  Pod::Usage            $Pod::Usage::VERSION\n",
      "  Getopt::Long          $Getopt::Long::VERSION\n",
      "  strict                $strict::VERSION\n",
      "  Perl                  $]\n",
      "  OS                    $^O\n",
      "  TkRolerCoaster.pl     $VERSION\n",
      "  $0\n",
      "\n\n";
      exit;
}
[download]

Thank you!