With all these cool responses, it is clear I needed to write myself a palindrome checker. So here goes.

#!/usr/bin/perl -w

use warnings;
use strict;

my $text;
for my $file (@ARGV) {
  {
    local $/=undef;
    open my $fh, '<', $file or die;
    $text = <$fh>;
    close $fh;
  }
  $text =~ s/\s//g;

  if ($ENV{'debug'}) {
    print "forwards  = $text\n";
    print "backwards = " . reverse($text) . "\n";
  }

  if ($text eq reverse $text) {
    print "$file: Palindome OK.\n";
  }
  else {
    print "$file: NOT a palindrome.\n";
  }
}
exit 0;
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This didn't seem worthy of a separate Cool Uses for Perl posting.

EDIT: Fixed based on JavaFan's comments. I no longer split the text and flip it to compare, and I do a string "is equal" compare instead of re match.