As you can see, these cellular automata I calculated can be represented by 9 bits (8 for rules + 1 for starting pattern).

Actually, 1/4 of these automata are generated a similar way in one of the examples of Mathematica. My solution is not much more difficult to write, but it needs nothing but Perl.

Question: Is there an easy way to do this with strings and substitutions (or bitwise string ops) instead of arrays and map? Is that faster?

Update 2012-12-16: see also Game of life ran by unpack function.