darkroom mode for emacs on osx (from http://draketo.de/light/english/simple-emacs-darkroom)

darkroom.el

; simple darkroom with fullscreen, 
; fringe, mode-line, menu-bar and scroll-bar hiding.
(defvar darkroom-enabled nil)

(defun toggle-darkroom ()
  (interactive)
  (if (not darkroom-enabled)
      (setq darkroom-enabled t)
    (setq darkroom-enabled nil))
;  (hide-mode-line)
  (if darkroom-enabled
      (progn
        (fringe-mode 'both)
        (menu-bar-mode -1)
        (scroll-bar-mode -1)
        (set-fringe-mode 200)
  (ns-toggle-fullscreen))
    (progn 
      (ns-toggle-fullscreen)
      (fringe-mode 'default)
      (menu-bar-mode)
      (scroll-bar-mode t)
      (set-fringe-mode 2))))

; Activate with F11 - enhanced fullscreen :)
(global-set-key [f11] 'toggle-darkroom)