You may have noticed there is a Skype status now available in this forum (the other IM apps are pretty standard). If you want to use this, you have to first enter your user info for Skype into your profile (User CP), then you have to make your status available for web applications via Skype software.
For Mac, go to Skype Preferences, go to the Privacy tab, and check the box allowing your status to be seen on the web.
There you have it (it can take a moment for this to actually show up).