Google has added a new featured to its search listings albeit without a lot a fuss. If you look underneath the Google logo on a search results page above the first listings you will now see a text link stating "show options".
When clicked on this introduces a new range of search filters allows users to select results from videos, forums, reviews, and also by various time criteria i.e. past 24 hours of past year. I mentioned Google's move to Universal search in my post regarding the Wolframalpha search engine and this is another step towards that.
An excellent view and description of this new development, far better than i can explain, and including a link to a Googles video explaining the new options can be found on the Further blog from Mark Cook its search marketing director which is well worth a read here: http://www.furtheronline.co.uk/blog/New-Google-Search-Options-132