derp.rb

class Derp < Rubot::WebResource
  get :chuck, 'http://4q.cc/index.php?pid=fact&person=chuck' do |doc|
    if fact = doc.css("#factbox").first
      fact.text.strip
    else
      "fail"
    end
  end
end

test_controller.rb

class TestController < Rubot::Controller
  command :chuck do
    reply Derp.chuck
  end
end

web_resource.rb

module Rubot
  class WebResource
    def self.get(name, url)
      define_singleton_method(name) do
        response = Net::HTTP.get(URI.parse(url))
        yield Nokogiri::HTML.parse(response)
      end
    end
  end
end