gistfile1.rb

# In application_controller

def current_postal
  @postal_code ||= PostalCode.find_first_valid_in_united_states(
    [params[:postal_code], previous_postal_requests.last, postal_from_geoip, 90013],
    :include=>:territory)
end

# In postal_code.rb

def self.find_first_valid(zip_codes_to_try, options = {})
  zip_codes_to_try.each do |zip|
    found = PostalCode.find_by_postal_code_and_country_name(zip,'United States', options)
    return found if found
  end
end