Julien Klepatch

Events RSVP is a plugin to create RSVP forms for events and manage registrations.
Events are created from a custom menu in the admin and integrated to the website 
thanks to a custom widget, located in the widget menu.
Users can:
<ul>
<li>Register for the event</li>
<li>Register for the waiting list if the max registration limit has been reached</li>
<li>Receive confirmation emails after successful registration for the event or 
for the waiting list</li>
</ul>
Admin can:
<ul>
<li>See the list of people registered for the event and for the waiting list</li>
<li>Modify the max registration limit</li>
<li>Cancel any registration</li>
</ul>

Events RSVP

Easily create an RSVP form and manage registrations

Jan Štětina

This plugin allows network admin to send organizational messages to blog admins within blog administration.
Main features:
<ul>
<li>Every blog admin sees an notification until they mark all messages as read.</li>
<li>Network admin has control over these notifications – can view who has not read which message yet and can delete notifications manually</li>
<li>Message contains title (with or without URL), current date and the content (which can contain HTML)</li>
<li>Notifications are shown to admins of blogs active in time of it’s creation. (probably will be adjustable in the future)</li>
</ul>
Makes use of the WordPress Logging Service.
Developed for private use, but has perspective for more extensive usage. I can’t guarantee any support in the future nor further development, but it is to be expected. Kindly inform me about bugs, if you find any, or propose new features: <a href="mailto:zaantar@zaantar.eu?subject=[organizational-message-notifier]" rel="nofollow ugc">zaantar@zaantar.eu</a>.
<h3>Wishlist</h3>
<ul>
<li>accept list of usernames as a target when creating new message</li>
<li>rewrite code using PHP 5.3 features such as namespaces</li>
<li>more verbose error logging</li>
<li>bulk actions in message table</li>
</ul>

Organizational Message Notifier

Allows network admin to send organizational messages to blog admins. Includes read confirmation.

Events RSVP vs Organizational Message Notifier