Recently I bought a new iPhone, then I went to visit my friend wiht my iPhone. My friend knows that iPhone not only can telephone, but also can play movie and music, so he let me show iPhone to him, then he found a music was wonderful on my iPhone and wanted to copy it to his computer, but my friend only has a Mac PC, which I have never used it, so is there a simple way to copy music from my iPhone to his Mac OS ?

I think you need an application which can transfer iPhone, iPod files back to Mac.