my $stable      = "1.8";
my $unstable    = "1.7.2";

my @mirrors     = ('http://www.foo.com/bar/stable',
                   'http://stable.example.com',
                   'http://downloads.site.org/$stable',
                   'http://www.unmetered.org/data',
                  );

print "Mirror: $mirrors[rand @mirrors]";