Originally Posted by Etarip

So you want the sharing in iTunes only with the additional capability to download the music. You want it to be limited by invitations rather than the local subnet.

The closest thing that comes to mind is using ourTunes to grab files from iTunes shares. I'm not sure but I think outTunes may also be able to jump subnets. You could also hook up an invite only system by having a password known by the entire group that everyone uses to password protect their shares.

Please note that invite only systems are not immune to prosecution, DC++ uses a system like this but nodes still get sued.