Update: official blog post from Google.
In September we announced that we were working to bring Google Instant to mobile, and today we’re making a beta version available to most iPhone and Android devices in the U.S. To try it out, go to google.com in your phone’s browser and tap the Google Instant “Turn on” link beneath the search box (if you don’t see the “Turn on” link, try waiting a moment and then refresh the page).
Like the desktop version of Google Instant, when you type on your mobile device you’ll see predictions of what you might be searching for. If you type [anse], for example, you should see [ansel adams] along with other predictions.
We hope you’ll enjoy using Google Instant for mobile as much as we enjoyed making it. It’s currently available for Android 2.2 (“Froyo”) devices and iPhones and iPods running iOS 4 in the U.S. in English.
According to a screenshot posted by 9to5mac, Google has started rolling out the Instant search to iOS devices. In the screenshot, you can see it’s labelled as “beta” and you have the option to turn it off.
The guys at 9to5mac haven’t managed to get the option in New York, and we haven’t either with our VPN to San Francisco. It’s not available in Italy either, so I assume it’s a slow roll-out in certain US states. We’ll keep you posted.