They're not making any more real estate; not until we colonize other planets at least. Laying out our dead horizontally, and leaving them in peace forever, is becoming an expensive proposition. That's why inventor Donald Scruggs has come up with the screw-in coffin.
Holding a body vertically, it is screwed down into the ground securely, to optimize graveyards' use of space.
It can be screwed in manually or with a machine, and designed to take into account the density of the earth where it's used.
Scruggs has installed the prototype above in his own California backyard, and is working on refining the idea. He even envisions a transparent model for those wishing a glamorous burial.