"Langton's Virtual Ant" by nowak
http://mikenowak.ca

To read about Langton's Ant, go to:
http://mathworld.wolfram.com/LangtonsAnt.html
Requirements: Flash 6 Player (simply because of MX's built in
compression... the file can be Flash 4 compatible without it.)
Recommendations: if it seems really small, try to scale the
flash file up. If it seems blurry, right click and set the
quality to "low."
Notes: it takes a while before the pattern shows up, so be
patient.