Hey Dirje and Bart-Jan,
Yes I agree with you that it would be very functional to make the chat option on the website "shout box" so that you can chat with the online persons immediately.
I followed your advise Bart-Jan and looked on the Joomla page. There is a "AJAX shoutbox" download there (this is a Joomla module, an extension of the already existing website) that adds live chat functionality to your Joomla site. The visitors can chat with each other right in the website without refreshing their browsers. It's almost like chatting on an instant messenging network. It's all powered by AJAX, a hot new old technology that powers things like Gmail, Google Maps and other brilliant web apps. By downloading this we can get a piece of all this in the alumni site. Installing instructions are that you install the component and module inside the zip file.
Maybe this is a suggestion, so I will also bring it to the attention of the people in the homepage group.
Tessa
You will find it on:
http://extensions.joomla.org/