Like IRC, you can use Skype to create public or private chat-rooms for both internal and external communication (see Skype help).
You will see a list of useful commands by typing '/help' in the chat field.
Skype should only be used for non critical communication. When important things need to be signed-off, you may prefer another way.
The original document is available at http://www.heraprocess.doleans.net/tiki-index.php?page=using_skype