I see that AWStats uses maxmind's GeoIP 'Perl API'.
I know you can obtain CIDR country nets from ftp.(apnic)|(arin)|(lacnic)|(afrinic)|(ripe).net, yet they all have different ftp dir tree's which makes creating modules for such a use hapless -- unless they 'honest to god' kept those ftp dir tree's constant (do they keep their dir tree's constant?).
On a different subject. Country CIDR-net firewalling is something that a lot of countries/orgs/individuals practice these days. It's quite sad. But you have to do it when you have to do it.
marto, have you used AWStats? Is it stable? And have you used Maxmind's GeoIP Perl Module (either one) on its own?