Text Expander
http://wordpress.org/extend/plugins/text-expander/
http://en.www.ali.dj/wordpress-plugin-text-expander/
Allows you to define areas of text that expand/collapse when clicked.
A double-arrow is shown next to the expand-link, which indicates whether the part is collapsed or expanded next.
The expand-part will expand via a jQuery-animation. This looks a lot better, than having the text just appear all of the sudden.
*Alternativy*
Adjustly Collapse
http://wordpress.org/extend/plugins/adjustly-collapse/
http://www.psdcovers.com/adjustly-collapse/
This plugin allows authors to link 2 html elements together as trigger and target. When the trigger is clicked the target will immediately expand to reveal its content.
