in reply to Finding out which country a user comes from using $_ENV[HTTP_...]

I found this thread when trying to answer the same question. As rob_au suggested, I tried Geo::IP but my ISP doesn't support it (they have the module, but it needs a separate database file that has to be updated). I didn't have the necessary expertise to install the current version (it comes with a C library) and I couldn't make Geo::IP::PurePerl work. In the end I plumped for Geo::IPFree which I installed without trouble. It has a slightly simpler interface if all you want is to extract the country name and short code:
use CGI; use Geo::IPfree qw(LookUp); my ($countrycode,$country) = LookUp($cgi->remote_host); print $countrycode,"\n",$country;
Returns, for example:
GB United Kingdom

George Sherston