Langton's ant was used as an example of scientific ideas in Terry Pratchett's book about science in his fantasy world (which my brother gave me as a present last christmas, thank you).

I searched and found implementations:
http://www.mathematische-basteleien.de/ameise.htm

and a definition:
http://en.wikipedia.org/wiki/Langton's_ant

and an applet that works (yeah, java rocks)
http://users.libero.it/acnard/ant.html