$("p").hide();
$("a").click(function () {
$(this).next("p:first").slideToggle("fast");
});

Here’s a version for lists that can be used to build an accordion navigation menu:

$("ul li ul").hide();
$("a").click(function () {
$(this).next("ul:first").slideToggle("fast");
});

Thanks to this post on Stackoverflow for the inspiration:

http://stackoverflow.com/questions/248320/using-this-with-jquery-selectors/248335

My selectors allow you to have multiple questions listed on one page. The answers given to the question on Stackoverflow only allowed for one, since, if clicked, it would toggle ALL of the paragraphs simultaneously.