One thing I sometimes like to do is to create, from scratch, a minimal Linux system.

For example, I can take the Linux kernel, compile it for User Mode Linux (basically, the kernel is running as a user process in a host Linux system, sort of like a virtual machine), create a basic filesystem with busybox (a program that can emulate many standard UNIX/Linux utilities), and run that minimal system. There isn't that much I can do with it (though I can mount the host filesystem, chroot into it, and do all sorts of things without needing root on the host), but it can still be fun to play around with.

I can, for instance, experiment with the various features of the Linux kernel without needing a full install.

I think that, once I get around to ordering a Raspberry Pi Zero, I might try running a minimal system of this sort on it; for my purposes, this means I can make the entire thing read-only so that I don't lose data when power is cut. (This is especially important since I might be powering it solely from the USB port of a computer.)

(By the way, anybody have any suggestions about where the best place to order one is?)

At the end of a stormy relationship, you might get this.