Mafia Wars is a multiplayer browser game created by Zynga. It is on several social networking sites and on the iPhone.
Mafia Wars is set in New York City and Little Italy, with the option for players to travel between New York, Cuba (level 35+), Moscow (level 70+) and Bangkok (upon unlocking items from New York levels, level 18+). In 2010, Paris, London and South Africa are introduced as challenge missions (which are available for a limited time). Las Vegas is released in June 23 as the fifth city available. The game revolves around doing and mastering jobs to earn cash and experience, with the goal of establishing and advancing one's criminal empire. Players create mafias by recruiting players and using reward points to hire extra mafia members. Social networking sites such as Facebook, MySpace and Friendster allow players to recruit from friends to build their mafia and fight against other players. Players can also improve their stats by visiting the Godfather (ie, making a micropayment).
Source: Wikipedia, "Mafia wars," available under the CC-BY-SA License.