Vladimir Prelovac

WP Wall is a “Wall” widget that appears in your blog’s sidebar acting as a cool shoutbox for your visitors.
The comment will appear in the sidebar immediately, without reloading the page.
All comments are internally handled by WordPress so that means you have normal comment moderation, SPAM protection and new comment notification.
WP Wall is fully customizable with a CSS file and included graphics.
WP Wall features: 
* Global commenting “Wall” 
* Comments are handled entirely by WordPress 
* RSS Feed for the Wall 
* Smilies 
* Instant delete for admin 
* Option to display HTML and make links clickable 
* Navigation through pages 
* Interactive Wall: It can automatically refresh turning into a chat
Plugin by Vladimir Prelovac. Also check out <a href="https://managewp.com" rel="nofollow ugc">ManageWP</a>.
<h3>License</h3>
This file is part of WP Wall.
WP Wall is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
WP Wall is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with WP Wall. If not, see <a href="http://www.gnu.org/licenses/" rel="nofollow ugc">http://www.gnu.org/licenses/</a>.

WP Wall

"Wall" widget that appears in your blog's sidebar acting as a cool shoutbox for your visitors.

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.

WP Wall vs Random Post Box