In fact mac has this nifty speech recognition built-in to the OS that simply can be turned on from the preference and includes a fair decent command set. What makes it more powerful is that the command set can easily be extended by applescript and attached to individual programs. It also works fairly well with video games, like World of Warcraft and I am sure with other games. There are a few things with the speech recognition that need to be taken into consideration when using it for gaming.