The new voice-activated Google Mobile app for the iPhone is finally here.
It is freakishly accurate. It's not perfect, but it's extremely good. Good enough to be used frequently,
The service bungled one nearby restaurant, but got everything else right. It uses the phone's location data to narrow down results. Try searching for "sushi" and you'll get your closest sushi restaurants at the top of your search results.
The Google Mobile app gives you its answers in text, which makes for a very quick experience. If your result returns phone numbers, you can dial the phone by clicking on one. But if you're driving in your car and need a quick connection, use Goog411 instead, which is a full voice-in, voice-out experience.
As others have noted, Google Mobile doesn't let you do voice dialing from your own contact list.
To get the app, visit the iTunes Application Store and search for "Google Mobile App." [Source]