Synchronizing Itunes with my iPhone, home PC and my Notebook?

I have an iPhone4, a home PC with Win7 and a Notebook with Win7. All of them have iTunes on them, but the majority of the music I have is on my home PC. Is there some way I can sync all 3 of them together so if I download a song on my Notebook it'll turn up on my iPhone home PC and visa-versa?