Collapsible text block

Hello,
I’ve been looking for a wordpress plugin to create collapsible text, or text you can toggle between hide/show.
This would be very useful for many purposes, not least for tests where you could hide the answer.
These are some examples of what I would like:
http://snippets.wikidot.com/code:collapsible-text-block
http://educational.pbwiki.com/HideDivs
http://snippets.wikidot.com/code:collapsible-text-block
http://www.dynamicdrive.com/dynamicindex17/switchcontent.htm
Any help would be appreciated.