put this in features/support to enable remote running of cucumber selenium tests

remote.rb

# HOST_OF_SELENIUM_BROWSER_SERVER=10.0.2.2
# HOST_OF_APP_BEING_TESTED=33.33.33.10
if ENV['HOST_OF_SELENIUM_BROWSER_SERVER'] and ENV['HOST_OF_APP_BEING_TESTED']
  # if capybara supported this type of approach: http://selenium-client-factory.infradna.com/
  # this code could be removed
  require 'selenium-webdriver'

  profile = Selenium::WebDriver::Firefox::Profile.new
  profile["network.http.use-cache"] = false

  Capybara.register_driver :selenium do |app|
    Capybara::Driver::Selenium.new(app,
      :browser => :remote,
      :url => "http://#{ENV['HOST_OF_SELENIUM_BROWSER_SERVER']}:4444/wd/hub",
      :desired_capabilities =>     Selenium::WebDriver::Remote::Capabilities.firefox(:firefox_profile => profile)
    )
  end

  class Capybara::Server
    def host
      ENV['HOST_OF_APP_BEING_TESTED']
    end
  end
end