Earlier this month Google unveiled search options providing new filters and displays for web search results, these include timeline and wonder wheel. Wonder wheel is a mindmap-like graphical cluster view. Timeline clusters results (based on dates in the results text) on a timeline, and allows narrowing or broadening the search time frame. There is also an option to show related searches.
To access the new features click on "Show options..." at the top of a Google search results page (line where number of results is shown). This opens a panel with controls for the new options, clicking on "Hide options..." sets you back to traditional view.
The announcement post at the official Google blog has a short video tour of the new search options features.