Serendip has some fun, interactive exhibits about Langton's Ant and The Game of Life:

http://serendip.brynmawr.edu/complexity/models/langtonsant/

and

http://serendip.brynmawr.edu/playground/life.html

Other Serendip interactive exhibits are available on Serendip's Playground:

http://serendip.brynmawr.edu/playground/