The CerfCube is a small (3 inches on each side) cube that holds
a StrongARM-based single-board computer running Linux. It's built
as a blank slate for OEM's. This article offers some in-depth info
on the device.
"The Linux CerfCube comes complete with a Linux kernel
and Apache web server, and sells for $379 at quantity one.
The CerfCube is basically a miniature Linux "box" consisting of
a StrongARM-based SBC (called a CerfBoard) enclosed in a cast
aluminum cube, three inches on a side. Do the math: with a
CerfCube, you can fit a complete (networked) Linux system in just
0.015 cubic foot!"