Mindshare Labs, Inc.

jQuery Notify: a fast and easy way to display notifications on your website. Some possible uses:
<ul>
<li>Form validation (“Please fill out all of the fields.”)</li>
<li>A welcome message the first time someone visits your site.</li>
<li>Newsletter subscription form</li>
<li>Submission confirmation: (“Message sent. We’ll be in touch soon.”)</li>
<li>Breaking news, updates, special offers</li>
<li>Advertising</li>
</ul>
Try a <a href="http://jquery-notify.mindsharelabs.com/" rel="nofollow ugc">demo</a>.
<h4>Features:</h4>
<ul>
<li>Can be used on a per-page basis with a shortcode, or embedded directly into your template</li>
<li>Elegantly styled and animated in W3C valid HTML5 and CSS3, without any images</li>
<li>Animation speed and delay settings available from the shortcode</li>
<li>Comes with four styles: ‘default’ (blue), ‘error’ (red), ‘warning’ (orange), and ‘success’ (green)</li>
<li>
Supports unlimited user-created styles
We’ll be working to add new features as we think of them. Please comment in the forum if you have any 
feature requests.
</li>
</ul>

jQuery Notify

An attractive, lightweight, and highly configurable jQuery notification pane.

.fay

Notify all WordPress users (and not only the admin) on every post publishing. The notification is only sent on the first publishing action and not after every update.

WP Post Notifier For All

Notify all Wordpress users (and not only the admin) on every post publishing.

jQuery Notify vs WP Post Notifier For All