Google introduces four new 'gadgets' to its search offering.

Google Co-op adds community expertise to your search results. Google even uses the space for the top sponsored links for this feature.
Every individual or organization can setup a Google Co-op profile to annotations, links and tags to topics. Google’s algorithms add this 'meta information' in your search results.
I have setup a Co-op profile for I4U NEWS, subscribe it here.
Google Trends lets you examine billions of searches conducted on Google to gain insight into broad search patterns over time.

The new Google Desktop 4 comes with a couple of new improvement and features.

Google Notebook allows you to clip text, images, and links from the pages they're browsing, save them to an online "notebook" that is accessible from any computer, and share them with others.
More details about the new Google features can be found in this press-release.