I do mine by source. I have CDs for Daz, RDNA, Poser World and Poser Style plus ones for Fantasy, Vicky, Mill Girls, Mike etc. I also have CDs for my pictures (photoshop ones take up so much space if you want to keep them in layers) and backgrounds etc. Thank goodness that CDs are cheap. I am also about to buy a new second hard-drive - and I thought that I would never fill 40 gb!