Digital asset management is one of the biggest hidden costs of digital photography. Not only in hardware, but in TIME. One of my time saving goals for the year is to get another studio assistant who can sit there and take care of all that time wasting work. People think the darkroom is tedious - jeez, sitting at the computer, retouching, managing files, uploading to the lab, now that's tedious.
It's amazing how quickly you can put your hands on a negative, even in the absence of a formal filing system. Open up a binder, flip a few pages and there it is!