TCBarrett

This plugin requires is just the front end javascript library, the following two things to be done in support: 
1. Add the class ‘simpleajaxform’ to your form. 
2. Make sure you have the correct wp_ajax handler hook defined.
It was primarily built as an example for a blog post.

Simple AJAX Form

A simple jQuery javascript library to ajax enable forms.

Xoda

Random Post Box is a plugin that lets you place a box anywhere on your blog, with template tag or shortcode, and 
load random posts with an interval and fade effect. It uses jQuery (Ajax) which means that the content is loaded without 
loading the rest of the page. The timings can be set in the admin options-panel.
The template tag is <code><?php random_post_box(); ?></code>. You can also use the shortcode <code>[random-post-box]</code> in a page or post.
<h4>Features</h4>
<ul>
<li>Insert placeholder with template tag</li>
<li>Insert placeholder with shortcode</li>
<li>Set time for displaying the post</li>
<li>Set times for fade in and fade out affect</li>
<li>Exclude or include posts by category</li>
<li>Exclude posts by age (in days)</li>
<li>Use title only</li>
<li>Use post excerpt or bodycontent</li>
<li>Strip tags from body</li>
<li>Show/hide post metadata</li>
</ul>

Random Post Box

The Random Post Box plugin places a box anywhere on the blog, where it loads random posts one-after-the-other.

Simple AJAX Form vs Random Post Box