Suppose you are at work, but all your iTunes are at home, and you would really like to listen to them. Suppose it is the other way around, because your cable modem doesn't upload fast enough. Here's your salvation:
Note that if iTunes isn't used for a bit of time, the tunnel will shut down and need to be reopened. To make life easy, put the following in your .bash_aliases
file:
alias iTunesTunnel="ssh -f -g -L 4689:127.0.0.1:3689 -l username -N music_server_ip"
You need to substitute your own port number (for the 4689), user name, and music server's ip address.
After you do this, all you need to do is type iTunesTunnel
in the Terminal, enter your password, and start listening again.