A handy new feature is now available for handsets running Android 2.2 (FroYo) or higher, as well as iOS (4.0+) devices. Google Instant for Mobile works in a similar way to its desktop equivalent, displaying a snapshot of a webpage before it is opened, giving a rough overview of the content. This makes it easier for you to find what you are looking faster and eliminates the need to switch back and forth between the webpages and the results page.
The Google Mobile Blog describes how to use Instant Previews on your mobile, and also provides a video demonstration:
To use Instant Previews on your mobile device, do a search on www.google.com and tap on the magnifying glass next to any search result. A side-by-side comparison view of the webpage previews for the first page of search results will appear. When you find a result you like, tap on the preview to go straight to the website. It’s as easy as finding a recipe for poaching an egg: