Hi, I'm a programmer, but am completely new to iPhone development. I am still learning how the Core Location / GPS development works, but so far have not found the answer to this. How do apps like Yelp or AroundMe know the Business Name, address and phone number data in the area. Obviously, there's some data store that gets queried, but do they maintain their own database of this information or is there a service that anyone can use to get the same information? In other words, where do Yelp-like apps get that data? Thanks!