Map Types
Oddly, you can't set the map type before a center coordinate is given. This works:
overviewMap = new GMap2(document.getElementById("overviewMap"));
overviewMap.setCenter(new GLatLng(39.943860, -75.126443), 16);
overviewMap.setMapType(G_HYBRID_MAP);
But this doesn't:
overviewMap = new GMap2(document.getElementById("overviewMap"));
overviewMap.setMapType(G_HYBRID_MAP);
overviewMap.setCenter(new GLatLng(39.943860, -75.126443), 16);