IP2Location is a C library that enables the user to find the country, region,
city, latitude, longitude, zip code, time zone, ISP, domain name, connection
type, area code, weather, mobile network, elevation, usage type by IP address
or hostname originates from.  It contains a demo IP2Location IP-COUNTRY BIN
database which consists of real data for IP address range 0.0.0.0 to 99.255.
255.255.  This database contains IP address blocks as key and countries as
values.

WWW: http://www.ip2location.com/c.aspx