>>6
Good idea. Here is the code. Whole thing is pretty slow though.
To >>8,9,10, look at the topic thanks, faggots.

use File::Find;

sub wanted {
    $flen = -s $_;
    push @{$sizees{$flen}}, $File::Find::name if -f;
}


find \&wanted, ('.');

while (($k,$v) = each(%sizees)) {
    if (scalar @$v > 1) {
        foreach (@$v) {
            push @{$dups{substr(`md5sum "$_"`,0,31)}}, $_;
        }
    }
}

while (($k,$v) = each(%dups)) {
    if (scalar @$v > 1) {
        print "$k:";
        foreach (@$v) {
            print " [$_]";
        }
        print "\n";
    }
}