Here's a useful little program i found.
The free Hamachi desktop application gives you secure, zero-configuration LAN over the internet. Any app that works over a local network can be used with Hamachi over the internet, like Windows file sharing, iTunes, Remote Desktop, FTP, VNC and gaming. All of Hamachi's connections are secure, encrypted, authenticated and peer-to-peer. Though Hamachi acts as a mediator between your computers and creates the tunnel for their communication, Hamachi's servers don't listen in on or log your activity.
Some situations you might use Hamachi:
* You're on the road with your laptop and want secure access to your PC's files.
* Your office or dorm room computer is behind a restrictive firewall that doesn't let you reach it from the internet.
* You want to add encryption to insecure network protocols like VNC.
* You want to set up a shared folder of files for friends and family to access.
Sound useful? Let's get started.
Set up Hamachi
1. Download and install Hamachi. For the most part, the Windows installation is the usual "just click next" routine, except for two notes: Hamachi will attempt to install a virtual network adapter which Windows XP says is not supported. - just hit the "Continue Anyway" button at that point. Also, if you have Windows Firewall enabled (or any firewall, for that matter), it will ask if you want to allow traffic to and from the Hamachi client. You do. Click the "Unblock" button to allow Hamachi traffic through your firewall, as shown.

2. Create your Hamachi network. Once Hamachi's installed it will walk you through a quick tutorial to get you started. Read it - it's worth it. Then, hit the network button (bottom right hand corner, second button to the left) and choose "Create new network" from the menu. Give your network a name (mine was "gtrap-home") and a password (if you'd like.) Click the Create button.

Now your computer will be a member of the new network, and get its own Hamachi IP address (in addition to its regular IP address). It will also have a nickname that will identify it on your network.

The reason why i brought this to your attention was to create a network in which we can all share itunes music with each other.
enable the sharing feature withing itunes, and then you'll be good to go.
This could also be useful for everyone playing Ikariam to chat and do stuff like that so i created the network called: SRFI
Of course you can then all create your own personal networks for whatever uses.