jQuery Toggle Text?

$(function() {
    $("#show-background").click(function () {
        $("#content-area").animate({opacity: 'toggle'}, 'slow'); 
    });

    var text = $('#show-background').text();
    $('#show-background').text(
        text == "Show Background" ? "Show Text" : "Show Background");
});

Toggle hides or shows elements. You could achieve the same effect using toggle by having 2 links and toggling them when either is clicked.

The most beautiful answer is... Extend jQuery with this function...

$.fn.extend({
    toggleText: function(a, b){
        return this.text(this.text() == b ? a : b);
    }
});

HTML:

<button class="example"> Initial </button>

Use:

$(".example").toggleText('Initial', 'Secondary');

I've used the logic ( x == b ? a : b ) in the case that the initial HTML text is slightly different (an extra space, period, etc...) so you'll never get a duplicate showing of the intended initial value

(Also why I purposely left spaces in the HTML example ;-)

Another possibility for HTML toggle use brought to my attention by Meules [below] is:

$.fn.extend({
        toggleHtml: function(a, b){
            return this.html(this.html() == b ? a : b);
        }
    });

HTML:

<div>John Doe was an unknown.<button id='readmore_john_doe'> Read More... </button></div>

Use:

$("readmore_john_doe").click($.toggleHtml(
    'Read More...', 
    'Until they found his real name was <strong>Doe John</strong>.')
);

(or something like this)