Nick Bosch

<p>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!</p>


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.

.dan

<p>This plugin allows you to communicate with other registered users of you wordpress blog/website/portal easily inside admin interface. There is possibility to create groups, assign users to them and communicate only with users from the selected group.</p>


SmokeSignal

Really simple plugin that allows you to communicate with users inside wordpress

Simple, but useful

Send internal messages between registered users in admin section.

WP Dashboard Chat vs SmokeSignal