The Facebook JavaScript SDK, the one we will be using for our app, enables us to access all of the features of the Graph API via JavaScript, and it provides a rich set of features like authentication and sharing. In this tutorial I'll show you how to use this SDK in your site. I'll show you how to add some features to an application we built-in my previous tutorials, the distance finder (part1 of the tutorial, part2). As you might remember, we've also added twitter @anywhere features to the app (the tutorial), now it's time to add Facebook as well!