Google Instant automatically refreshes the search results as you enter new keywords. So far, the new beta version works if you go to www.google.com (English) and click the link that turns on the beta feature.
– Google Instant for mobile phones works best with 3g connection or over wireless networks. Because the quality of different network connections can vary, we’ve made it easy to turn the service on and off without leaving the search page, Google said in a blog post.
According to Google, the service only works on iPhones running iOS 4.0 or and Android 2.2.