via Google Mobile Blog by Lawrence Chang on 12/18/08
Whether you're using Google search through the search widget on the Android home screen, the built-in search box of the iPhone's Safari browser, or google.com on either device, you'll now end up with search results optimized for your phone. In some situations, you've already been seeing the new search results pages. Now, all Google search options for Android and iPhone lead to results that load faster and are formatted to fit the screen so you don't have to zoom or scroll side-to-side. We've also added touchscreen-friendly buttons and expandable maps for local business results.
The optimized search results pages are currently available in U.S. English for Android and for iPhone and iPod touch devices with firmware 2.x. If you prefer, you can always view desktop search result pages by selecting the "Classic" link at the bottom of any page.Posted by Steve Kanefsky and Rob Stacey, Software Engineers, Google mobile team