The Skype Internet calling service lets you broadcast your mood to the other Skype users in your contact list. The Mac version of the Skype client includes the ability to display the song you are currently listening to in iTunes as your Skype mood. This feature can be toggled on and off in the application's preferences, allowing you to show the Skype users in your contacts list what you are listening to in a few simple steps,
Click the "Finder" icon in the computer's dock, followed by the "Applications" folder icon. Double-click the "Skype" application icon to launch the application.
Click the "Skype" tab and select the "Preferences..." option. Click the "General" tab to view the Skype application's general preferences.
Place a checkmark next to the "Set current iTunes song as my Mood Message" option. Click the "X" in the upper left corner of the preferences pane to close the window and save the settings. Now, the song you are listening to in iTunes will be displayed as your Skype Mood Message.