Facebook is making a ton of announcements about their new Graph Search. ... Some of the features demoed today within Graph Search:
* Search for friends by where they live, where they work, who they are friends with.
* Search for photos of friends based on where they were taken, how many likes/comments they have, when they were taken.
* Search through photos you have liked Search for local businesses, like restaurants, based on where your friends have gone.
* You can refine by place type, liked by, places in (location), Visited by (My friends), similar to Foursquare.