Microsoft's Bing for iPhone went live yesterday, and is now available in the iPhone application store. You can read more about it here on PC World.com. I downloaded the app last night on my wife's iPhone and it's working great!
The Speech team here at Microsoft has been working with Bing on the Voice Search capabilities for a while now, and the whole team is excited that the latest version of our speech technology is powering the newest version of Bing's mobile client software.
I especially like how easily you can get to movies, stocks, and images, with simple voice commands. Download the app, and try it out for yourself.
Let us know what you think of the Voice Search capabilities!