Apple introduced the Game Kit API

As part of iPhone OS 3, Apple introduced the Game Kit API. Game Kit is a new framework that aims to solve two main problems facing application and game developers. The first problem is the ability to create ad hoc peer-to-peer networks among devices within close proximity to each other. To satisfy this need, Game Kit provides a sophisticated, yet simple-to-use mechanism for doing exactly this over the Bluetooth networking capability built into iPhone and the second-generation iPod Touch. The second problem is the ability to add in-game voice to applications.