Google search has shown Instant Previews next to the results that it displays on desktop browsers for some time now. As of today, mobile browsers can also use Instant Previews!
When searching on a compatible smartphone there will now be a magnifying glass next to each item returned. Tapping on that magnifying glass brings up a thumbnail view of the results which you can swipe from side to side. When you find the page you’re looking for simply tap on it and the full version of the page will open. It’s a fast and interactive way to determine if you really want to go to a certain page before navigating away from your search results.
Google Instant Previews is available on Android Froyo 2.2 and above, and Apple’s iOS (4.0+) devices, and it’s available in 38 languages.
Source: Google Mobile Blog