gistfile1.el

(let
    ((marmalade '("marmalade" . "http://marmalade-repo.org/packages/"))
     (melpa '("melpa" . "http://melpa.milkbox.net/packages/"))
     (org '("org" . "http://orgmode.org/elpa/")))
  (add-to-list 'package-archives marmalade t)
  (add-to-list 'package-archives melpa t)
  (add-to-list 'package-archives org t))

(package-initialize)

(unless (and (file-exists-p "~/.emacs.d/elpa/archives/marmalade")
             (file-exists-p "~/.emacs.d/elpa/archives/gnu")
             (file-exists-p "~/.emacs.d/elpa/archives/melpa"))
  (package-refresh-contents))