The situation: I have a Macbook Air, and a lot of lossless music on my NAS. My Air won't hold all the music, but I do want some of it to carry around. How exactly do I do this? I want to be able to change what to have on the Air when I feel like it, so I'm not really into just moving some of the library to the Air - and other players are also accessing the NAS, so everything has to be at both places. Am I missing something obvious - I can't quite get my head around what the most efficient way of doing this is... Any input is appreciated.