Collapsible page elements with DOM - A tutorial on how to create an 'expand / collapse' elements in your page. This tutorial to accompany the Onelinetools.org script: Evolt.org - Collapsible elements.
A tutorial exploring a couple ways to show and hide details by clicking on headings. There's also basic show and hide and slicker show and hide with pretty effects.
Unobtrusive javascript for applying expand/shrink behaviour. Script generates buttons and apply behaviour on them for divs which have a class name 'collapsable'.
Designing tree menus with separation of content, presentation and behaviour. Uses JavaScript (jquery) to both show and hide nested DIVs rather than using CSS to hide the nested DIVs so it still works with JavaScript turned off and without CSS working. This means no JavaScript and CSS dependency.