Tried Maxmind in version 3.0, but 2 of my clients couldn't use it, so I've ditched it and now I use two external services: http://who.is, http://www.geoplugin.net.

git-svn-id: https://plugins.svn.wordpress.org/admin-block-country/trunk@774425 b8457f37-d9ea-0310-8a92-e5e31aec5664