djhoward, if you used the location hack that Joe wrote for those of us using the simulator (see http://forums.bignerdranch.com/viewtopic.php?f=79&t=2069) then the app worked by displaying Apple HQ.
The simulator is running on a laptop or desktop and those do not have the same GPS hardware and location services for cell towers as the iPhone (see Page 80 where the book is discussing the distanceFilter property). Thus, he had to “hardcode” coordinate values into the app to force it to see a location and thus allow the app to work when running on the simulator.
If you ran the app from the beginning on an iOS device (iPhone/iPad) then I don’t think you needed the extra code. It is helpful to note that the authors did put a note in the Introduction that stating getting fully credentialed by Apple was best because you test the app on a device. I’m only on Chapter 5 and I’ve run into two problems not being able to use my device (taking a screenshot and the location hack). I’m thinking it is time to start the ball rolling on a full Dev license!