custom_steps.rb

Given /^I visit subdomain "(.+)"$/ do |sub|
  #host! "#{sub}.example.com"  #for webrat
  Capybara.default_host = "#{sub}.example.com" #for Rack::Test
  Capybara.app_host = "http://#{sub}.example.com:9887" if Capybara.current_driver == :culerity

  ################################################################################
  # As far as I know, you have to put all the {sub}.example.com entries that you're
  # using in your /etc/hosts file for the Culerity tests.  This didn't seem to be 
  # required for Rack::Test
  ################################################################################

end

my_feature.feature

Scenario: This is a Rack::Test scenario
Given I visit subdomain "test"
And I log in as user "someone" with password "test"  #another custom step
Yadda Yadda

@culerity
Scenario: This is a culerity scenario
Given I visit subdomain "test"
And I log in as user "someone" with password "test"  #another custom step
Yadda Yadda