I found this product mentioned on Timebomb 2000:
The FIFO Systems Food Storage Rack
During the discussion of this product, several folks noted that it isn't very space efficient--you can stack more cans in the same space. As someone who used to stock shelves, I can tell you they're right--sort of.
Per the product specs, it can store 54 10.75 ounce cans in a space 12" x 16" x 16". In that space, it gives you the benefit of being able to top load the rack and pull from the bottom. It's a true First In, First Out (FIFO) storage system for cans.
Now you can stack more (not many more, but more) cans in that space. However, if you're trying to properly rotate you stock, using the oldest first, every time you restock you will have to pull it all off the shelf, put the new stuff in back, and then restack the shelf.
It's a pain, and it takes a lot of time. My time is valuable to me, and when I can buy some of it back for a fairly inexpensive price, I'll do it. It also makes keeping a pantry easier, and when you can make it easier, a family who might not be as motivated as they should be on this subject are more likely to keep one. That's a Good Thing.
As The Freehold moves into the new digs, I'm going to be reorganizing our preparations for bad times. I'll most likely be purchasing a few of these racks, and if I do, you'll get a first-hand report.