Is a Skype on-line status icon required?
Well ICQ has this feature, and as you probably know by now then I've made a Skype add on to download here:
http://moodle.org/mod/forum/discuss.php?d=17006
But in my experience it is sufficient to see if a user has Skype and to know if he/she is online or not. Why is that?
Well, it comes to my mind, that if you like Skype so much that you would like your classmates/colleagues to Skype you - then you have clicked the Skype feature that starts Skype when your computer starts. So voila: all you need to know is if the user is on-line on the course 
If, you some how for a different reason needs to know then this site can provide you with the on-line Skype status. But then you need to register one extra account to the Skype account you have already! The site is located here: http://www.jyve.com/
What is your experience?
BR
Jens Gammelgaard