Mobile devices are so useful because they can get on the net with their built-in wi-fi or cellular data radios. But how does this work? In iOS, we have a slew of networking APIs, each appropriate in different situations. From decades-old BSD sockets to the new-in-iOS-5 iCloud, there are a wide range of networking calls available to your app, and an equally wide range of semantics in how to use them. In this talk, we'll start with high-level abstractions like iCloud and other objects that can either load from or save to a URL, then progress down through the stack, grabbing arbitrary content from URLs, self-networking with Bonjour and Game Kit, and finally accessing the socket layer with CFNetwork and BSD sockets.