I was wondering if anyone can help me? This query comes in two parts . For the non Sony NW-HD sytems . Does anyone know how play-lists are handled on your system. I believe I have read that many players are able to cope with play-lists without having multiple copies of the track on the unit, and that play-lists can also be created on the go i.e. without the use of the PC/Mac. So I was wondering how this is achieved in a technical sense i.e. files structures, where/how the info is stored? For the HD3 camp . Does anybody know the specific workings of the NW-HDx in terms of its bookmark functionality? This feature proves (to a certain degree) that it should be able to cope with a proper playlist, whereby only one copy of the track is required. As the system is presumably adding some additional data to the file information, to denote this track should be included in the bookmark list. I would assume (maybe wrongly) that each of the bookmarked tracks has a file pointer to the previous and next tracks from the bookmark list. Does anyone know how this is actually handled in terms of the file structure? Or where the bookmark info is stored? Thanks in advance for any info or insight into this.