If you use iTunes while your computer is hooked to a network (work, dorms, and coffee shops are good examples), you can share your iTunes with other people. This feature has been around for a long time in iTunes. Something that isn’t included is the ability to see how many, and who is listening to your music.
I did a little bit of searching an found that iTunes uses port 3689 to share music on. Reaching back into my DOS days, I came up with this:
press the windows key + r
enter “cmd” and press enter
at the prompt type:
netstat | find “:3689”
you will get a listing of all the computers connected to your iTunes. A useless but interesting trick.
If you are running a mac, I’m sure you can do the same thing but with grep.