Yes, there is. The first module you should look at is File::Find, available as a core module, or some of its "relatives" available from CPAN.

Said this, your question is slightly ambiguous. For if there are duplicate filenames you may have conflicts when trying to move them into "results". If you don't care about this a very rough primer may be along these lines:

#! /usr/bin/perl -l

use strict;
use warnings;
use File::Find;
use File::Basename;

@ARGV = grep { -d or !warn "`$_': not a directory!\n" } @ARGV;
die "Usage: $0 <target> <source> [<sources>]\n"
  if @ARGV < 2;

my $target=shift;

find { no_chdir => 1,
       wanted => sub {
           return unless /\.output$/;
           my $dest="$target/" . basename $_;
           rename $_, $dest or
             warn "Can't move `$_' to `$dest': $!\n" and
             return;
           print "`$_' => `$dest'\n";
       } }, @ARGV;

__END__
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Things you should particularly care about when refining this include:

• trailing slashes: a relevant module may be File::Spec,
• checking the destinations.