Hide-Show mode gives you the ability to code fold reasonably intelligently. Hit a key, fold the code. Hit a key, unfold the code. It's particular handy for Lisp use, I've noticed. I've been able to use it for Python as well.

Here's some snippets

(global-set-key "\M-`" 'hs-toggle-hiding)

(add-hook 'c-mode-common-hook 'hs-minor-mode)
(add-hook 'emacs-lisp-mode-hook 'hs-minor-mode)
(add-hook 'java-mode-hook 'hs-minor-mode)
(add-hook 'lisp-mode-hook 'hs-minor-mode)
(add-hook 'perl-mode-hook 'hs-minor-mode)
(add-hook 'sh-mode-hook 'hs-minor-mode)

Or, to start it, M-x hs-mode.


Reference: http://www.emacswiki.org/cgi-bin/wiki/HideShow