You can print unique values in array order using a variation on the standard hash trick:

my %unique;
@unique{@values} = ();

for (@values) {
    next unless exists $unique{$_};
    print $_, $/;
    delete $unique{$_};
}
[download]

Update: A simpler way that leaves you with the %unique hash populated:

my %unique;
for (@values) {
    next if exists $unique{$_};
    print $_, $/;
    $unique{$_}++;
}
[download]

After Compline,
Zaxo