title: When calculating a distance from a city, how can I factor in the approximate size (physical area) of the city?
body: <p>I'm building a store locator based on in-house geocoding data.  Effectively I need to query stories near City X or Zip Y within a certain radius.  The data sets I'm working with are relatively comprehensive and include things such as population.</p>
  
  <p>One issue is that large cities (Los Angeles for example) are many miles in radius so you could be within the city but miles from the coordinate we have loaded.</p>
  
  <p>Is there a rule of thumb, or a free data feed which would list an approximate radius of a city, or perhaps even outlines of the city points?</p>
  
  <p>Also, assuming I have a shape defining the city what calculation would I use to say "stores within X miles of this area"?</p>