Social gaming startup Zynga is seeing some impressive traction. It now boats 129 million monthly active users across its portfolio of more than 30 games, according to both Inside Facebook's AppData(see chart) and Developer Analytics. That's up from about 50 million three months ago, and 30 million in April. Zynga's most popular games are FarmVille (the most popular game on Facebook with 50 million cumulative players), Mafia Wars (the second most popular game on Facebook with 25 million), Zynga Poker, and YoVille.