Every time I go to San Francisco, I think to myself, "I'm pretty sure I know a lot of friends who live here, but can never remember who they are." Inevitably, 5 minutes after I get on the plane to go home I remember 2 or 3 people that I totally forgot lived there and would have liked to see.

Who Lives Here solves this problem. Just connect to Facebook, type a place, and it will tell you all the friends you know that live there. It works for really specific places, like "Palo Alto, CA," or broad ones, like "France."

You'll be amazed who you know in cities around the world. Never travel lonely again!