Yahoo's Mindset

Yahoo's Mindset is an intent driven search engine.  An innovative addition to the user interface is a slide bar at the top of the search page.  It allows users to resort their results based on their focus.  Want more commercially focused results?  Slide the bar to the left.  More research focused results can be displayed by sliding the bar to the right.  Using machine learning technology, the web results are graded on a scale from -2 (most commercial) to +2 (most informational).  You can read more about it here.