Phonegap Geolocation - how do I tell if my user is close to landmarks?

Question

Can someone give me a simplistic overview how I would be able to tell if my user was near, say a certain retail store or landmark, etc.?

I know how to get coords with phonegaps geolocation api but not sure how to determine what is near that?

This is essentially what foursquare, google maps, etc does (heck they even know what TYPEs of businesses they are)...

Can someone clue me in please?

Answer 1

Two parts to this:

1. Distance between two lat/lng points - see this answer https://stackoverflow.com/a/8914832/156477 (specifically the part about getting distance between lat/lng points).

2. Where do you get the list of landmarks.... this is the bigger issue. You could try using a service like Frommers or Eventful, or if you're happy to go with Google, use their relatively new Places API (and the Google solution means you can skip step 1).