automatic encrypting decrypting with emacs

I have been for long time wondering if there was a way to automatically encrypt and decrypt files when accessing them, not leaving an unencrypted file around.

Today I have an epiphany: "let's see if emacs can do that". As an emacs power user I felt as an idiot. Emacs has in the core this ability since emacs 23!! and I never realized about it :-(.

Emacs has incorporated the EasyPG code into its core.
http://www.emacswiki.org/emacs/EasyPG

 Things can not be more easy. Put in your .emacs

(require 'epa-file)
(epa-file-enable)

;; as it is annoying to be asked if I want passphrase or publick/private key
;; I set passphrase as default
(setq epa-file-select-keys nil)

I also would like to have a gpg agent cache. In ubuntu 12.04 the package is called gnupg-agent

sudo apt-get install gnupg-agent
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  libassuan0 pinentry-gtk2
Suggested packages:
  pinentry-doc
The following NEW packages will be installed:
  gnupg-agent libassuan0 pinentry-gtk2
0 upgraded, 3 newly installed, 0 to remove and 1 not upgraded.  

Now you only need to open a file ended with .gpg and automatically emacs would ask you for the pasword for decryption and again for saving. No unencrypted temporary files are stored, or at least I am not aware of them.