googlemaps.txt

init file
GOOGLEKEY='AIzaSyBYPC8Wothfroho8ub3yM6wHtOE--Oovng'

application.html.erb
<%= javascript_include_tag "https://maps.googleapis.com/maps/api/js?key=#{GOOGLEKEY}&sensor=false" %>

google.js
var map;
var canvas;

$(function(){

});


function display_map(lat, long, zoom)
{
  var mapOptions = {
    center: new google.maps.LatLng(lat, long),
    zoom: zoom,
    mapTypeId: google.maps.MapTypeId.ROADMAP
  };

  canvas = $('#map_canvas')[0];
  map = new google.maps.Map(canvas, mapOptions);
}

function add_marker(lat, long, title)
{
  var latlng = new google.maps.LatLng(lat, long);
  var marker = new google.maps.Marker({position: latlng, map: map, title:title});
}



show page:
<div id="map_canvas" style="width:300px; height:300px;"></div>

<script>
  display_map(<%= @ninja.lat %>, <%= @ninja.long %>, 10);
  add_marker(<%= @ninja.lat %>, <%= @ninja.long %>, 'nyc, baby!');
</script>