routes.rb

  resources :channels do
    resources :posts do
      member do
        put :disable
        put :toggle_stickiness
        put :add_channel
      end 
      resources :replies, :only => [:index, :new, :create, :show]
    end 
  end 

  resources :posts do
    member do
      put :disable
      put :toggle_stickiness
      put :add_channel
    end 
    resources :replies, :only => [:index, :new, :create, :show]
  end

Check out my fork that DRYs it up with a shallow block http://gist.github.com/515537

Rails commit: rails/rails@6db9558