Devise logged in root route rails 3

Heyya guys. So i thought about this coolio idea, if you are logged in then you get some sort of dashboard, else you get an information/login/sign up page.. So how do i do that..

I mostly wants to do this in Routes = not something like

def index
  if current_user.present?
    render :action => 'logged_in'
  else
    render :action => 'logged_out'
  end
end

thanks in advance!

/ Oluf Nielsen