When Google released Instant Previews on SERP’s late last year, it enhanced the search experience and made usabililty more convenient in finding quality search results. This great feature has now been released for mobile devices running Android (2.2+) or iOS (4.0+). Simply click the magnifine glass on the right hand side of search results for a snap preview of the webpage. Nice feature is that after you click to preview, you can scroll across and instantly preview the other websites in one easy step. Then simply select the website that looks most relevant in the preview and enjoy. See Google Mobile for further instructions.
Source: Official Google Blog