--- a/web/data/cubicweb.gmap.js	Wed Jan 04 17:21:14 2012 +0100
+++ b/web/data/cubicweb.gmap.js	Mon Jan 09 16:20:49 2012 +0100
@@ -23,9 +23,24 @@
             var jsonurl = wdgnode.getAttribute('cubicweb:loadurl');
             var self = this; // bind this to a local variable
             jQuery.getJSON(jsonurl, function(geodata) {
+                var zoomLevel;
+                var center;
+                var latlngbounds = new GLatLngBounds( );
+                for (var i = 0; i < geodata.markers.length; i++) {
+                    var marker = geodata.markers[i];
+                    var latlng = new GLatLng(marker.latitude, marker.longitude);
+                    latlngbounds.extend( latlng );
+                }
+                if (geodata.zoomlevel) {
+                    zoomLevel = geodata.zoomlevel;
+                } else {
+                    zoomLevel = map.getBoundsZoomLevel( latlngbounds ) - 1;
                 if (geodata.center) {
-                    var zoomLevel = geodata.zoomlevel;
-                    map.setCenter(new GLatLng(geodata.center.latitude, geodata.center.longitude), zoomLevel);
+                    center = new GLatng(geodata.center.latitude, geodata.center.longitude);
+                } else {
+                    center = latlngbounds.getCenter();
+                }
+                map.setCenter(center, zoomLevel);
                 }
                 for (var i = 0; i < geodata.markers.length; i++) {
                     var marker = geodata.markers[i];

--- a/web/views/igeocodable.py	Wed Jan 04 17:21:14 2012 +0100
+++ b/web/views/igeocodable.py	Mon Jan 09 16:20:49 2012 +0100
@@ -62,7 +62,7 @@
     content_type = 'application/json'
 
     def call(self):
-        zoomlevel = self._cw.form.pop('zoomlevel', 8)
+        zoomlevel = self._cw.form.pop('zoomlevel', None)
         extraparams = self._cw.form.copy()
         extraparams.pop('vid', None)
         extraparams.pop('rql', None)
@@ -74,15 +74,13 @@
                 continue
             markers.append(self.build_marker_data(entity, igeocodable,
                                                   extraparams))
-        center = {
-            'latitude': sum(marker['latitude'] for marker in markers) / len(markers),
-            'longitude': sum(marker['longitude'] for marker in markers) / len(markers),
-            }
+        if not markers:
+            return
         geodata = {
-            'zoomlevel': int(zoomlevel),
-            'center': center,
             'markers': markers,
             }
+        if zoomlevel:
+            geodata['zoomlevel'] = zoomlevel
         self.w(json_dumps(geodata))
 
     def build_marker_data(self, entity, igeocodable, extraparams):