I am pleased to announce a new RubyForge project I call CreditCard ( http://rubyforge.org/projects/creditcard/ ). This is a small hint of what is to come, a full payment processing gateway for Ruby. To try it out, type: gem install creditcard These subroutines tell you whether a credit card number is self-consistent using known algorithms for credit card numbers. All non-integer values are removed from the string before parsing so that you don’t have to worry about the format of the string. Here are some example uses. "5276 4400 6542 1319".creditcard? => true puts 5276440065421319.creditcard_type => "mastercard" "5276440065421319".creditcard? "visa" => false "5276-4400-6542-1319".creditcard? "mastercard" => true -Lucas http://www.rufy.com/