Sometime today, the new version Google Mobile Apps for the iPhone will be available and it has added voice control.
Users can speak search queries into their iPhones to get results from the web and find their contacts. The app detects when a voice/head is near the phone. It can also detect users' locations.
Be sure to talk clearly. We once asked for towing via a voice controlled app and got back, "There are no listings for Tony" in the area.