Music Tracker is an accessory for the Pidgin (previously known as Gaim) instant messaging program. This application for Pidgin lets you show to each of your contacts the audio track you are playing at that time.
The best feature of Music Tracker is that it shows all the information on your file, like the artist name, the album, track, duration, progress, etc. All this data is taken from the program used to play this music. It works well with Winamp, Windows Media Player, iTunes and Foobar2000 in Windows, and many others in Linux.
Also, so your friends can see this information, they don`t need to install any other application, as Music Tracker can send this data via diverse messaging programs, like AIM, Yahoo, MSN Messenger, etc.
NOTE: On the Music Tracker author`s website there is another version of the program compatible with Linux.