iPhone App Review: Apple's Remote works, and it's free
Just pop open remote, click to add a new library, and then enter the resulting 4 digit code in iTunes to give your iPhone access to your library. Now you've got an interface that looks just like the one you use to play music on your iPod. This'll work with any iTunes equipped computer on your network, and once you've set them up, you can switch between them easily. We even set up a little ad-hoc network with just a Mac and an iPod Touch, and Remote's performance was excellent. Did we mention it's free?