I am running out of space on my laptop drive. After weighing all my options, I have decided to down convert all the songs in my iTunes library to 160kbps (they are all currently 320kbps) to create more drive space. Does anyone know if there's a way to down convert all the songs in my library to a lower bit rate at once? I know there's an option to down convert songs to 128kbps when transferring them to an ipod. I basically want to do the same thing but with the 200GBs of music I have in my iTunes library. Any suggestions?