Example from http://griffin.oobleyboo.com/archive/facebooker-and-cucumber/

basic_facebooker_steps.rb

Given /^I am logged in as a Facebook user$/ do
  # Initialize facebooker session
  # This will set all the parameters that FB normally passes through, as well as set up
  # a default Facebooker::Mock::Session. It all just magically happens from this one liner.
  @integration_session = open_session

  # Now, we need to specify the default options for the request - in this case, we're setting
  # that the FB UID is 1, and they have the friends defined in FACEBOOK_FRIENDS - simply UIDs separated by commas.
  @integration_session.default_request_params.merge!( :fb_sig_user => 1, :fb_sig_friends => '2,3' )
  
  # If you need to make FB requests in your steps, you can use @integration_session to make them - they
  # will then go through the fixtures defined elsewhere.
end