I've recently built a simple messaging system for some work colleagues and I am currently working on optimizing current functionality. Many users are complaining of a messy-looking message display system.
The thing that I currently have in place is a PHP file inside of an iFrame that refreshes every 15 seconds. However this is undesirable and wastes resources.
As a result I was wondering if there are any tutorials out there that propose better methods, similar to those used by Facebook whereby the comment is automatically loaded upon posting.
http://ajaxim.com/ <-- Ajax Instant Messaging framework. :)
EDIT :
You might also want to try this http://www.smashingmagazine.com/2012/05/09/building-real-time-commenting-system/ which is a good that guides you through making a realtime comment system. That system is built using HTML 5. (PHP and Ajax too of course) And it's using Websockets :)
Oh, and a link to a previously asked question that is similar: Instant notification using php/mysql,please give me a general idea