I had picked up a sleeve of 20 of these large plastic cups for $.50 back in February from my local Habitat Restore thinking that I may have use for them in the wedding decorations that I was working on for my brother-in-laws upcoming wedding. (needless to say that I did not end up using them for that but) While trying to select a color off the shelf I have caused yet another landslide of spray paint sending cans all over the place and one ended up landing inside of one of these cups. It was at that time I discovered that the bottom of the cup perfectly held the spray paint can and I could lay it on it's side and even stack the cups!
I simply lined the cups up on a scrap piece of plywood and screwed them down using a small wood screw and a washer. These are pretty durable cups that don't crack when you squish them but I figured the washer would help disperse the weight more evenly across the bottom. I then mounted the board to the wall and filled the cups with spray paint cans and found that I could even fit a can in the dead space between each cup. Now I have I can quickly see my color choices and make a selection without the fear of breaking a toe!