I found a free script that lets you determine the status of an icecast channel. You could use it to display the online/offline status to listeners. From the downloaded files the interesting one is mnt_check.php. Try the demo below to get a demonstration of the functionality.

Update:
I have moved the online tester to a separate location.

Channel online

Channel offline

This article is an idea of live streaming with instant feedback from listeners. There are quiet a few source clients that can generate direct streaming from OSS, ALSA audio devices. When using more advanced musical softwares in Linux, especially when running them in sync the sound engine and routing is handled by Jack. Therefore you need a source client capable of dealing with Jack to forward the sound to the streaming server. Internet DJ Console fulfills the requirement. Furthermore it delivers an ogg output stream, which enables you to easily embed it on a website with the audio tag implemented in the html5 standard.

To enhance the user interaction you could implement a chat/shoutbox on the station website. Bumpin is an alternative but I’m not fully satisfied with it’s loading time. If you know of any service similar to Bumpin, please direct me to it. Optimal would be something that can be installed on LAMP.