Was surprised to see just now that my MBA battery life was down to 2.46 hrs yet recently fully charged. Then I realised that iTunes was still running. Sure enough I quit iTunes and battery life immediately leapt to over 4 hours. I can only assume that this is because iTunes was linked to my new ATV. If I leave my wifi network, will iTunes still look for my ATV or do I need to remember to switch output back to my MBA speakers? Its not a problem as such - just need to be aware. Ultimately I intend to get an iMac or Mac Mini to run iTunes (and for other things) but thats not a priority right now.