I wonder if anyone can point me in the direction of something that would solve this problem for me ... first a bit about my setup.

At home I have a 24" iMac which hosts the library for my iPod (a 16Gb Touch), with all my music files being stored on a NAS drive under our stairs. For safety purposes, I have a nightly backup job which copies my music files from my NAS drive to a 2.5" external drive hooked up to my iMac.

When I go off on holiday, I tend to take my MacBook with me and use it as a media centre (through Front Row). Ideally I'd like to now use the 2.5" backup so that I have my entire library with me without having to load it all onto the MacBook. The problem I have is that while my iPod library is up to date on the iMac, every time I look to use the external drive with my MacBook I need to manually re-import any new music which has been added to the drive since the last sync.

So at last the question ... is there an app I can run on my MacBook which automatically adds new music found on the external drive to my iTunes library? So that iTunes monitors the folders and adds automatically? Would be great if it did, as would save me doing what I have to at the moment - delete the library on the MacBook and re-import the whole folder structure again.

Any advice appreciated.