It's just a hash ref so dereference it with the key you want. E.g.,

use warnings;
use strict;
use WWW::Mechanize;

my $mech = WWW::Mechanize->new(
                               stack_depth => 0,
                               autocheck   => 0,
                               onerror => undef,
                              );
$mech->agent_alias("Windows IE 6");
$mech->get("http://cnn.com");

for my $link ( $mech->links )
{
    print "  URI: ", $link->url_abs, $/;
    print "Title: ", $link->attrs->{title} || "[n/a]", $/, $/;
}

__END__
  URI: http://www.cnn.com/
Title: [n/a]

  URI: http://edition.cnn.com/
Title: CNN INTERNATIONAL

  URI: http://www.cnnmexico.com/
Title: CNN M?XICO

  URI: javascript:cnn_initeditionhtml(3);
Title: [n/a]
[download]

As you can see from México, there may be encoding issues you'll need to address.