I use CD cases as storage. Removing the black CD tray, leaving the clear, plastic case, one empty container fits 18 used bottle caps in a hexagonal pattern, or 14 unused bottle caps.

This stack of CD cases contains 300 bottle caps.

The trays run chronologically to when they were added to the website. The case number appears beneath each bottle cap (U001, N022). Combined with the search feature of the website it helps keep track of what bottle caps I already have.

The trays are stacked in a wood and glass cabinet. Each stack has thirty trays so it's easy to do the math to get the total (30 x 18 = 540 bottle caps). Currently the cabinet still has room for another three stacks - after that, larger furniture will be in order.