Zynga the creator of the hugely successful Farmville game are now seeing massive growth with their new Facebook game, CityVille with over 26 million users signed up to play. CityVille allows users to create and run their own city and went live on December 2, 2010 and although free does include in program purchasing. Farmville transferrerd to the iOS platform earlier this year and joins some of their other iPhone titles there including, World Scramble Challenge, Live Poker, Mafia Wars, Street Racing and Vampires: Bloodlust. Perhaps CityVille will be heading there soon too.