Using GPS to find out exactly where you are is one of the more awesome powers of mobile devices. It also poses some of the toughest challenges to developers, who must prevent excessive battery drain and deal with insufficient accuracy. In this talk. Richard Süselbeck helps you face such challenges by answering questions like: How does GPS even work? Where did my battery go? Why does my phone think I'm in the middle of a lake? If you've ever wanted to understand how satellite navigation actually works, this is the talk for you.