check_friends_headless.rb

require 'mechanize'

fb_friends = []

# login
agent = Mechanize.new
page = agent.get("https://www.facebook.com")
next_page = page.form_with(:id => 'login_form') do |form|
  form.field_with(:id => 'email').value = 'username'
  form.field_with(:id => 'pass').value = 'password'
end.submit

i = 0
while true do
  page2 = agent.get("https://touch.facebook.com/profile.php?v=friends&startindex=#{i}")
  if page2.search("h3 a").count != 0
    page2.search("h3 a").each do |link|
      fb_friends << link.children.first.text
    end
    i = i + page2.search("h3 a").count
  else
    break
  end
end

fb_friends = fb_friends.uniq