title: GPS lookup and user preference
body: <p>I'm starting to dip my toes into LocationManager.  I've created a service which tracks GPS location (interval is more than 60000ms) and updates my application with user location so they can find stuff nearby.</p>
  
  <p>As I understand it, users can go into their preferences and disable GPS for a particular application.</p>
  
  <p>I would essentially like to offer my users two modes.  1) GPS.  2) If <strong>GPS can not pull, device does not have a GPS chip, or GPS is turned off for my app</strong>, I would like to allow them to type in their zip code (or maybe switch to cell tower lookup).</p>
  
  <p>The bolded text is what I'm interested in.  How can I tell if the device does not have GPS?  How can I tell if the user has disabled GPS for my application?</p>
  
  <p>Side question:  My service gets launched from my 2nd Activity.  I call stopService in the onDestroy method of this Activity.  If I back up to my 1st Activity and the 2nd Activity is destroyed, I still notice the GPS icon on my phone running.  Is stopping the service sufficient?  Or do I need to stop the LocationManager in the onDestroy of the service?</p>