Another improvement from Google is the Options panel. They call it “an experiment” so that’s why is not visible to everybody.
This tool on the left allows to restrict search results to a certain criteria, like latest items, videos, reviews (it weeds out the opinions and rating), forum posts and to specify the age of the document (when was originated).

In this panel there are two tools: the Wonder Wheel and the Timeline. The first one is a Flash-based interactive circle with connections, in wich the keyword is in the center and related terms with links around it. Clicking on one of this terms, it appears a new connected circle with its related terms. The results page changes with every click on a term according to the topic, as in the ordinary search. It’s been said to work quite smoothly. The timeline tool allows to restrict searches to a certain year. The fact that makes it different to the first time restriction is that the time is related to webpage content, not to the creation of the document.

To try it you have go to google.com and paste a code into the address bar and enter.
javascript:void(document.cookie=”PREF=ID=4a609673baf685b5:TB=2:LD=en:CR=2:TM=1227543998:LM=1233568652:DV=AA:GM=1:IG=3:S=yFGqYec2D7L0wgxW;path=/; domain=.google.com”);