Nick Bosch

WP Dashboard Chat allows admins to communicate via a widget which displays on the Admin Dashboard. It’s perfect for quickly getting messages out to all your sites writers or having a formal meeting. Features include, @ mentions and replies, live updating, Gravatar support, auto-linking and HTML formatting. Many more coming soon!

WP Dashboard Chat

WP Dashboard Chat is a Twitter inspired widget, which displays on the admin dashboard. It allows for quick communication between users and admins.

mutube

A neat little WordPress plugin to show your current online status on your blog, with Widget support for those that use them. The plugin is powered via onlinestatus.org and supports most IM services including AOL, MSN, Yahoo!, Jabber (inc. Google Talk), Skype and ICQ. Different servers and icon-sets are available so it should be possible to find something to match your own blog.
You can show as many or as few IM network icons as you like and all options are configurable through the control panel. The <a href="http://onlinestatus.org" rel="nofollow ugc">onlinestatus.org</a> servers do most of the hard work here & are worth as visit if you’re looking for a status indicator for a non-Wordpress site.
You can now include your online status in posts using [imonline] tag in any page/post. The tagline link to my website (mutube.com) may also be removed by using imonline_status( false ) to call the plugin. (Note: it is hidden by default when outputting into posts).
<h3>To Do</h3>
Old style image lookups (without caching) 
Network’s own icon methods

IM Online

IM Online shows your current online status on your blog. Currently supports AOL, MSN, Yahoo!,…

WP Dashboard Chat vs IM Online