monkeypatch Rails::Application.load_console to load app-specific .irbrc

application.rb

# taken from http://railsbros.de/2010/11/29/a-custom-irbrc-for-rails-3.html
# config/application.rb that is
module MyApp
  class Application < Rails::Application
    # config stuff comes here

    def load_console(sandbox=false)
      super
      if File.exists?(project_specific_irbrc = File.join(Rails.root, ".irbrc"))
        puts "Loading project specific .irbrc ..."
        load(project_specific_irbrc)
      end
    end

  end
end