The expand tag creates a expandable/collapsable container to hold your content and should be very handy when it comes to organizing tutorials or any other extensive posts.
To use it you would just do
[ expand=caption ]content goes here[ /expand ]
Example
Not only can text can be put in an accordion box. You can put anything that you would want in between the expand tags!
http://images.devshed.com/corp/img/current/ds_logo.gif