code: function(options) {
          var layer_defaults = {
            'interestingTagsExclude': ['source', 'source_ref', 
                'source:ref', 'history', 'attribution', 'created_by'],
            'areaTags': ['area', 'building', 'leisure', 'tourism', 'ruins',
                'historic', 'landuse', 'military', 'natural', 'sport'] 
          };
            
          layer_defaults = OpenLayers.Util.extend(layer_defaults, options);
          
          var interesting = {};
          for (var i = 0; i < layer_defaults.interestingTagsExclude.length; i++) {
              interesting[layer_defaults.interestingTagsExclude[i]] = true;
          }
          layer_defaults.interestingTagsExclude = interesting;
          
          var area = {};
          for (var i = 0; i < layer_defaults.areaTags.length; i++) {
              area[layer_defaults.areaTags[i]] = true;
          }
          layer_defaults.areaTags = area;
  
          // OSM coordinates are always in longlat WGS84
          this.externalProjection = new OpenLayers.Projection("EPSG:4326");
          
          OpenLayers.Format.XML.prototype.initialize.apply(this, [layer_defaults]);
      }
docs: Constructor: OpenLayers.Format.OSM
  Create a new parser for OSM.
  
  Parameters:
  options - {Object} An optional object whose properties will be set on
  this instance.