Ah-ha! The Google Mobile iPhone App with search-by-voice is available via the iTunes store now. I downloaded it last night and began playing around with it. I can definitely see it coming handy while being in the car trying to find restaurants in the area or looking up something I can’t figure out.
When I opened the App I was greeted by this boy, I’m assuming he’s hungry for a cheeseburger:

Then I hit the “Voice Search” button and got the “Speak now” screen:

After that it tells you that the App is working and then pops up with the search results. It’s really as easy as they have made it out to be.