Perhaps because of competition from Bing, Google has become interested in guided search. It already let you filter results by type, time, and other criteria. New, Google is adding a new set of options geared at making results more timely, newsy, and personal.
The new options include the ability to see results from only the past hour, or for a specific date range. You can also filter for results only from news, blog, or book search.
You can also select “fewer shopping sites” or “more shopping sites.” Or you can choose to only see new sites, and make the search more of a discovery tool.