gistfile1.rb

def me
  user_classes = ["User", "Account"]
  methods = [:email_address, :email, :username, :login]

  user_classes.each do |class_name|
    begin
      klass = class_name.constantize
      methods.each do |method|
        return klass.send("find_by_#{method}", "[email protected]") if klass.new.respond_to?(method)
      end
    rescue NameError
      # Move onto the next potential class.
    end
  end
end