It all started as I was driving around my neighborhood and saw that one of my neighbors was discarding some old kitchen upper cabinets. They didn't look so bad, so I threw them in the car and brought them home. I shored them up a bit and hung them using cleats. Then I saw this hidden opportunity to make another project... and since I didn't have a decent way to organize my sandpaper....well, you get the idea.
The sandpaper cabinet is just some scrap 3/4 ply and some wood panels I had laying around. The shelves pull out and are nothing more than 1/8 hardboard. It isn't elegant but it will get the job done...