Google Maps geocoding lookup function
You could, but don't have to, check your googleMaps variable to be falsy, instead of undefined or null.
To make this code more readable, you could seperate the function from your object. That way, if you have more functions, you have an overview of your object's implementation.




1.

old 

if (googleMaps === undefined || googleMaps === null)

new

if(!googleMaps)



2.

old

var googleMaps = {
  getLatLngFromAddressString : function(addressStr, callback){
  //...    
  }
}


new

var getLatLngFromAddressString = function(addressStr, callback){
//...    
}

var googleMaps = {
  getLatLngFromAddressString : getLatLngFromAddressString
}