Quantum::Superpositions offers an elegant solution:

use Quantum::Superpositions;

my $list1 = [1,2,3];
my $list2 = [4,5,6];

print "No common items" if all(@$list1) != all(@$list2);
[download]

Basically, if all of the elements in list1 are not equal to all of the elements in list2, that will print "No Common Items"

HTH

-Tom