The reason they haven't put FMI on the 3gs is because in about 6 month's time a new iPhone will be out. Not only that but they need to give something to the iPhone 4 that the 3gs doesn't have. The iPhone 4 doesn't offer much more then the 3gs, apart from a new design and a front facing camera their isn't much apart from the iPhone 4 and the 3gs, all things most people could live without.