The Knowledge Graph enables you to search for things, people or places that Google knows about—landmarks, celebrities, cities, sports teams, buildings, geographical features, movies, celestial objects, works of art and more—and instantly get information that’s relevant to your query. This is a critical first step towards building the next generation of search, which taps into the collective intelligence of the web and understands the world a bit more like people do.
Check it out: http://www.google.com/insidesearch/features/search/knowledge.html
http://support.google.com/websearch/bin/answer.py?hl=en&answer=2620861
http://youtu.be/mmQl6VGvX-c
