I have made a number of changes to your code. You were declaring @urls twice. You get a list of objects from the find_all_links method. You need to iterate over the list and get the URL of each object.
use strict;
use warnings;
use WWW::Mechanize;
my $agent = WWW::Mechanize->new();
my $regex = 'results';
my $url ='http://www.google.co.uk/search?hl=en&safe=off&q=intitle%3A%2
+2football+scores%22+inurl%3Aresults&meta=cr%3DcountryUK%7CcountryGB';
$agent->get($url);
$agent->agent_alias( 'Windows IE 6' );
my @urls = $agent->find_all_links();
foreach my $link(@urls) {
print "Link: ", $link->url(), "\n";
}
# print out the content of the current page for debugging
print $agent->response()->as_string();