In The Hitchhiker's Guide to the Galaxy by Douglas Adams, an Earthman is affronted to find that his planet's entry in the Guide consists only of the single word "Harmless". The Guide researcher reassures him that the next edition will improve upon this. The new entry will read, "Mostly harmless." The Guide also tells of the creation of earth by inhabitants of the planet Magrathea, as a giant computer. It also mentions that we are descended from middle men. The Earth is located in sector ZZ9 Plural Z Alpha.
The Earth seems to play a huge part in the Star Trek universe, the Doctor Who universe, and others.
wikipedia.org dumped 2003-03-17 with terodump