I found it strange that this guide is redirecting questions to a specific person. Heiko Webers' (@hawe) last blog post is a year and a half old, so it's not obvious that he's still active with Rails security. If he is, feel free to revert.
All sorts of useful information about every country packaged as convenient little country objects. It includes data from ISO 3166 (countries and states/subdivisions ), ISO 4217 (currency), and E.164 (phone numbers).