In itunes I presume? But to get music into itunes it plays silly buggers with the file names and type and whatever else. MP4 isn't a 'normal' video format though is it? The world revolves around mpeg... and yup divx is a no no. However, if you get any other brand of mp3 player *goes to amazon to copy the first list he finds* can deal with "AAC (.M4A) support along with MP3, WMA, WAVE and Audible, WMV and DivX/XviD support (320x240)" and I'm guessing you simply drag them from a folder on your hard drive to a folder on the device. Now someone please tell me why the hell apple have to be such awkward bastards?