Library to find the country that any IP address originates fromhttp://www.maxmind.com/
GeoIP is a C library that enables the user to find the country that any
IP address or hostname originates from. It uses a file based database.
This database simply contains IP blocks as keys, and countries as
values. This database should be more complete and accurate than using
reverse DNS lookups.
MaxMind offers a service where you can have your database updated
automically each month.