iTunes Streaming Over Network (Multicast)

Hello, i'm new on mac and i'm looking to share my music via streaming, with multicast IP.

Let me explain you, if i'm listening music with iTunes on my mac, i want to be able listen that music with VLC for example or any multicast client program, then i could have my music on my nice stereo without plugin any Line out

I have a macbook pro and it' very boring to have that line out always plug in to listen music i want to be able to move without having that line. But don't tell me airtunes i don't want to spend that much money for that
Thanks

The question is "how do you want to listen to that music elsewhere?" Wireless headphones, a stereo system somewhere else in the house? Would an FM transmitter do the job for you? It means using a radio elsewhere to listen to iTunes streaming. I use a Tevo brand FM transmitter. I can listen to iTunes just about everywhere on my property - as long as I have a radio with me.

In fact i would like listen to another computer (windows XP), which is plugged on my stereo... That's why i think the multicast is the best, there is a lot of multicast client on windows like VLC, and or even Winamp, so i'll open VLC and say to play the streaming of my mac.

But i'm ok to do anything if it's free or cheap, bluetooth, network,... What I want is that what is played by iTunes (or everything from my mac) can be forward into my stereo plugged on my windows XP PC.