Example imenu configuration

init.el

;; keybinding to summon up imenu
(require 'imenu)
(global-set-key (kbd "C-c C-d") 'imenu)

;; display current defun in modeline
(which-function-mode 1)

(custom-set-variables
 '(imenu-after-jump-hook (quote ((lambda nil (recenter 10)))))
 '(imenu-auto-rescan t))