Esa's Google Maps API v3 experiments. Circle overlay as a marker.

circle_as_marker.js

// http://koti.mbnet.fi/ojalesa/boundsbox/makemarker_circle.htm
/**
 * makeMarker() ver 0.3
 * creates Marker and InfoWindow on a Map() named 'map'
 * now creates alternatively a Circle if 'radius' option property is given
 * creates sidebar row in a DIV 'sidebar'
 * saves marker to markerArray and markerBounds
 * @param options object for Marker, InfoWindow and SidebarItem
 * @author Esa 2009, 2010
 */
var infoWindow = new google.maps.InfoWindow();
var markerBounds = new google.maps.LatLngBounds();
var markerArray = [];
var pointsArray = []; // new in v0.3 For simple polyline construction.
 
function makeMarker(options){
  options.center = options.center || options.position;
  if (options.radius) var pushPin = new google.maps.Circle({map:map});
  else  var pushPin = new google.maps.Marker({map:map});
  pushPin.setOptions(options);
  google.maps.event.addListener(pushPin, "click", function(){
    infoWindow.setOptions(options);
    infoWindow.open(map, pushPin);
    if(this.sidebarButton)this.sidebarButton.button.focus();
  });
  if (options.sidebarItem){
    pushPin.sidebarButton = new SidebarItem(pushPin, options);
    pushPin.sidebarButton.addIn("sidebar");
  }
  markerBounds.extend(options.position);
  markerArray.push(pushPin);
  pointsArray.push(options.center);
  return pushPin;
}

google.maps.event.addListener(map, "click", function(){
  infoWindow.close();
});


/**
 * Creates a sidebar item 
 * @constructor
 * @author Esa 2009
 * @param marker
 * @param options object Supported properties: sidebarItem, sidebarItemClassName, sidebarItemWidth,
 */
function SidebarItem(marker, opts){
  var tag = opts.sidebarItemType || "button";
  var row = document.createElement(tag);
  row.innerHTML = opts.sidebarItem;
  row.className = opts.sidebarItemClassName || "sidebar_item";  
  row.style.display = "block";
  row.style.width = opts.sidebarItemWidth || "120px";
  row.onclick = function(){
    google.maps.event.trigger(marker, 'click');
  }
  row.onmouseover = function(){
    google.maps.event.trigger(marker, 'mouseover');
  }
  row.onmouseout = function(){
    google.maps.event.trigger(marker, 'mouseout');
  }
  this.button = row;
}
// adds a sidebar item to a 
SidebarItem.prototype.addIn = function(block){ if(block && block.nodeType == 1)this.div = block; else this.div = document.getElementById(block) || document.getElementById("sidebar") || document.getElementsByTagName("body")[0]; this.div.appendChild(this.button); } // deletes a sidebar item SidebarItem.prototype.remove = function(){ if(!this.div) return false; this.div.removeChild(this.button); return true; } //Feel free to use/develop/molest the functions as you like.