(require 'iswitchb)

(defvar next-buffer-depth 0)

(defun next-buffer ()
  (interactive)
  (let (buflist len buf)
    ;; This is a stripped down version of `iswitchb-make-buflist'.
    ;; I want to use `iswitchb-ignore-buffername-p' instead of
    ;; duplicating the work.
    (setq buflist
	  (delq nil
		(mapcar
		 (lambda (x)
		   (let ((b-name (buffer-name x)))
		     (unless (iswitchb-ignore-buffername-p b-name)
		       b-name)))
		 (buffer-list))))
    ;; However, I do not want the current buffer in the list
    (setq buflist (delq (buffer-name) buflist))

    (if (eq last-command 'next-buffer)
	(progn
	  (setq len (1- (list-length buflist)))
	  (if (eq next-buffer-depth len)
	      ;; Just keep taking the tail of the list
	      (setq buf (nth next-buffer-depth buflist))
	    (progn
	      (setq next-buffer-depth (1+ next-buffer-depth))
	      (setq buf (nth next-buffer-depth buflist)))))
      ;; This is the first next-buffer
      (setq next-buffer-depth 0)
      (setq buf (car buflist)))
    (if (not buf) (error "No other buffers"))
    (switch-to-buffer buf)))

(global-set-key [f11] 'next-buffer)