Hi Martin,
I have attached below a very helpful thread which might be of assistance to you in setting up your system.
In addition to what Peter and Joe have noted, if you have a wireless network at home, you can connect wirelessly to the system, which is outlined in this thread. But basically all you need to do is..
1.get an apple Airport Express (wireless device about US$100+/-) connect it using your existing Ipod cable to the aux port.
2. get the AE to join your wireless network.
3. set up your itunes to find remote devices/speakers (refer to thread as it goes into detail on this).
You should then be set up to stream music to the system!
To get your iphone working as a remote, you have to download i-remote (from Apple) in itunes applications on your computer and then sync with your iphone. Then follow the setup guide and now you can control all your itunes on your PC desktop.
I suggest you can also go to Apple and read up on the AE / itunes / iremote for more info as well.
Have a read of this thread (note - read to the end, as remote buddy works, but if you just want music iremote is much more responsive, easier to use)... it should make everything clear for you, it did for me!
http://forum.beoworld.org/forums/t/8543.aspx?PageIndex=1
Good luck with it, it really is neat and simple.
Laurence.