In a major move to integrate personal search and Web search, Google (GOOG) is adding some users' Gmail into their search results as a "limited field trial," it said today. So when participating users search for "Amazon," information from their own recent purchase confirmation emails will appear on the right rail. Or, a user could type "my flights" as a search query, and see directly at the top of their search results some coming itineraries drawn from their flight confirmation emails. "This is a baby step in a really complicated area," said Sagar Kamdar, director of product management for universal search, speaking at a presentation of at the company's San Francisco office of a few expansions of its semantic search efforts. Kamdar noted that Google's Gmail index is larger or the same size as its Web corpus. Plus, adding users' personal email into search needs to be private and secure. "That is such a hard problem," he said. Users can opt into the field trial at g.co/searchtrial today, and they should expect a wait of a couple days for activation, said Kamdar. They can then collapse Gmail results and turn off personalization should they choose. (This story has been posted on All Things D, a website owned by Dow Jones.)