The Pi-calculating Life pattern that the New Scientist mentions was developed by Adam P. Goucher. I'm not positive if this has appeared on math-fun yet, but Andrew J. Wade has built a linear-time replicator in Life: http://pentadecathlon.com/lifeNews/2010/05/oblique_life_spaceship_created.ht... -tom -- Check out Golly at http://golly.sf.net/