Or for a similar, easier task, problem 3 "life" from this year's FARIO: http://orac.amt.edu.au/fario/11/problems_en.pdf

Here's case 8 to give you an idea: http://i.imgur.com/1fFzO.png :P

Test data here: http://dl.dropbox.com/u/76985/life-all-linux.zip