I know the AirPort Express lets you stream iTunes over a wireless network, but what I want to do is essentially the same thing over a wired network, without the expense of the AirPorts. I have found plenty of sharing apps, plus what iTunes has built in, but that isn't what I want. I don't want sharing, but streaming. Where anyone on the network can "tune in" to what I have playing on my computer. Is anyone aware of anything to do that? It seems like such a simple, obvious thing to have available, but I can't find any way to do it. All computers are Macs, BTW.