Locale::Geocode is a module that provides an interface with which to find
codes and information on geographical locations and their administrative
subdivisions as defined primarily by ISO 3166-1 and ISO 3166-2. It is the
most complete ISO 3166 module available on CPAN.

Also included are, where applicable, FIPS codes.

WWW: http://search.cpan.org/dist/Locale-Geocode/