<script src="http://maps.googleapis.com/maps/api/js?sensor=false&extension=.js"></script>
<script src="http://google-maps-utility-library-v3.googlecode.com/svn/tags/markerwithlabel/1.1.9/src/markerwithlabel.js"></script>
<h3>Looks for marker text overlap which is happening, but not always.</h3>
<input type="button" value="add 100 markers - still under a minute" onclick="clearExistingMarkers();addMarkers(100);" ></button><br>
<input type="button" value="add markers in increments" onclick="addMarkers($('#numMarkers').val(), true);"><input id="numMarkers" type="text" value="10"/></button><br>
<input type="button" value="clear markers" onclick="clearExistingMarkers();" ></button><br>
markers added <span id="span">0</span>
<div id="map"></div>