I'm using a Macbooks optical output to my B&K Ref 30.  I use it for music and movies.  I find Frontrow audio sounds better than iTunes.  I also want to use the Macbook upstairs with a small 2-channel setup.  Wondering if I should us the optical out (Musical Fidelity V-Dac) or USB (HRT Streamer).
   Right now upstairs I'm using an iPod video/docked, Audio Magnus Tweak Kitted Sonic-T amp and Paradigm Atoms.  Still surprised how good this little set-up sounds.