CountryWhois

CountryWhois is a utility for identifying the geographic location of an IP address. CountryWhois can be used to analyse server logs, check e-mail address headers, identify online credit card fraud, or in any other instance where you need to quickly and accurately determine the country of origin by IP address. 

What makes CountryWhois different from similar tools is its very high accuracy (over 98%), unprecedented speed of processing (a 100 MB log file is processed within one second), regular updates that keep the ever-changing IP  address database up-to-date, an array of supported import and export formats, command-line mode, and a convenient interface.

While CountryWhois is similar to SmartWhois in some respects, it is focused exclusively on IP-to-country identification and doesn't need to contact external Whois servers.
 

It is available from here.

This is a nice little product that will set you back about $30 and provides a bit more information than certain other products available.  The results below show the product most probably uses a reverse lookup to resolve the IP addresses and manages to accurately identify the country of origin.