canllaith discovered a very amusing program:
It is an aquarium simulator that is completely text-based. Quite fun to leave running on a spare Konsole (plus it has sharks, including the bloody splotches in the water, and pirate ships!)
You can find it http://www.robobunny.com/projects/asciiquarium/. For those who are of the Gentoo persuasion, I have the required ebuilds here.