Bing, Google, Yahoo. They all have a series of APIs you can call to use their services in your Metro application. one of the more compelling services is Yahoo!’s Local Search API which allows you to find local businesses based on latitude and longitude.
The latest version of the Local Search Web Service allows you to search the Internet for businesses near a specified location, and now returns both the latitude and longitude and Yahoo! user ratings of the establishment, as well as search by business categories.
First, get a key
Keys for Yahoo! services are easy to get. From what I can tell, most of their services are free for developers. And so is the developer key. So, navigate to here and get your key.