Comet and Prototype for Facebook Similar Notifications
Geeks out there.
If you don’t have Peer to Peer server or some advance technology based server with you. Comet Programming is the answer for real time notifications or Messages as well.
I wrote small sample code. You can download from http://hiteshjoshi.com/download/6
You need a account at http://hiteshjoshi.com/wp-login.php?action=register
which is absolutely free and you can have access to all the plugins/scripts and other helpful articles.
How to test demo : Load the url in different windows/systems/tabs and test it out ;)