Geolocation and Maps
The iPhone is one of the most popular devices for geolocation: users use it for everything from driving directions to finding a restaurant close to them. As a developer, you can get in on the geolocation game by using the Core Location framework, one of the most powerful and interesting frameworks in the iPhone SDK. It abstracts the details of determining a user’s location, and does all the heavy lifting for you behind the scenes. From there you can use the MapKit framework to embed maps directly into your views, and then go ahead and annotate those maps. I’ll deep-dive into both these topics in upcoming title Geolocation in iOS, by Alasdair Allan (O’Reilly).
Third-Party SDKs
The same book will investigate third-party geo-SDKs such as the Skyhook Wireless Local Faves and Spot Rank SDKs, along with coverage of SimpleGeo and SG Context and Places.