Nice hack if you're using my face-remapping-alist patch

[Miles Bader]

;; I find displaying mail/gnus in a variable-pitch font is especially nice,
;; if it's easy to toggle on/off, and you have a nice variable-pitch font
;; (I didn't, until I started using this; the variable-pitch font-family
;; I'm using, btw, is "charter" (which I think is a standard X font(?)),
;; with a :height scale of 1.1).

;;; This allows variable-width text to be turned on or off conveniently
;;; in a buffer:

(define-minor-mode variable-pitch-mode
  "Variable-pitch default-face mode."
  :lighter " VarPitch"
  (when (boundp 'face-remapping-alist)
    (let ((default-remapping (assq 'default face-remapping-alist))
          (remappings face-remapping-alist))
      (cond ((and default-remapping (not variable-pitch-mode))
             (setq remappings (remq default-remapping remappings)))
            ((and variable-pitch-mode (null default-remapping))
             (setq remappings (cons '(default variable-pitch) remappings))))
      (unless (eq remappings face-remapping-alist)
        (set (make-local-variable 'face-remapping-alist) remappings)
        (force-window-update (current-buffer))))))

(defun turn-on-variable-pitch-mode ()
  "Turn on `variable-pitch-mode'."
  (interactive)
  (variable-pitch-mode t))

(global-set-key "\C-cv" 'variable-pitch-mode)

;;; Turn it on by default in some modes:

;; mail sending:
(add-hook 'message-mode-hook 'turn-on-variable-pitch-mode)
(add-hook 'mail-mode-hook 'turn-on-variable-pitch-mode)

;; mail/news reading:
(add-hook 'gnus-article-mode-hook 'turn-on-variable-pitch-mode)

(defun gnus-summary-toggle-variable-pitch-mode ()
  (interactive)
  (with-current-buffer gnus-article-buffer
    (variable-pitch-mode 'toggle)))

;; Bind "F" to toggle variable-pitch-mode in the article buffer
;; (warning, "F" already has a standard binding, so change at will)
(add-hook 'gnus-summary-mode-hook
          (lambda ()
            (local-set-key "F" 'gnus-summary-toggle-variable-pitch-mode)))

;; -Miles
-- 
97% of everything is grunge