Facebook's chief executive Mark Zuckerberg has unveiled the social networking site's new "Graph Search" in California.
He said: "This is one of the coolest things we have done in a while".
"Graph Search is the kind of product that we love to build at Facebook - it's a big technology problem and it's also a big social problem".
He went on: "We're not indexing the web. We're indexing our map of the graph - the graph is really big and its constantly changing."