I work on projects that last for short to intermediate periods (6 to 18 months on average) and I learned that the standard-style shelves and cabinets are not as useful to me as this Ikea shelving unit. I now reserve a slot for each project and a couple slots for "to do lists" etc.
It works great. I have fewer long term files be ause I don't do much long-term work. In fact, I specialize in short-term relationships [wish I would have understood that a long time ago].