A few utilities of NirSoft, including CurrPorts, SmartSniff, NetworkTrafficView, and CountryTraceRoute (which has been released just a few weeks ago) now supports the free IP geolocation database of MaxMind, in addition to the support of software77.net IP to country database.
The database of MaxMind is larger than the database of software77.net, and for some of the IP addresses, city information is also provided.
In order to start using the MaxMind database with the NirSoft utilities specified above, simply go to this Web page, download the GeoLite City database in binary/gzip format (The filename is GeoLiteCity.dat.gz), and then put this file in the same folder where the .exe files of NirSoft utilities are located.
When you run a utility that supports this database, it automatically loads the database and uses it to display the country/city information for every IP address.