Fingerprinting web applications (Joomla, Mediawiki and Wordpress)

I just posted a document on fingerprinting web applications where I show
some ideas to remotely detect the version of Joomla, Mediawiki and Wordpress
(easily extended to other apps).

http://sucuri.net/?page=docs&title=fingerprinting-web-apps

There is also a live tool for you to test with any site:
http://sucuri.net/?page=docs&title=fingerprinting-web-apps#v6