How do I subscribe to this service?
Please go to the DO try this at home-section to subscribe.
How do I use this service after subscription?
In php you would write in an appropriate place:
$client = new SoapClient('http://stigbo.dk/ip2country/ip2country.wsdl');
$res    = $client->IpQuery($_SERVER["REMOTE_ADDR"]);
and then you can access the values: ctry, cntry, country, mesg by WLOG:
These represents the ISO2 country code, the ISO3 country code, the country name and a status message, respectively.