Hello, This question isn't specifically related to the MBA, but it is an issue I am sure many MBA users have come across or know how to deal with. I recently purchased a WD passport 250gb external drive, which I have loaded up with music, vids, etc. The drive is usually not attached, but when I am at my desk I will attach it for the added media library. What will happen when I add the music to iTunes from the external hard drive? I know it will work fine when plugged in, but what about when i'm using it away from my desk (i.e. without the external drive)? Will the music still stay in my library, but just not play (come up with the little (!) next to the file)? When I connect, will it play just fine? I also have some music on the computer itself as well, which is already in the library. I am thinking of creating a playlist "stored on the MBA" and that way, assuming the external HD isn't connected, I can just play off that or select from that playlist and know it will be playable. Anyways, if you have any experience, let me know! Thanks!