[Riim]

Попробуй так:

map.addOverlay(new GGeoXml("http://s/1.kml"), new GGeoXml("http://s/2.kml"));

или так:

map.addOverlay(new GGeoXml("http://s/1.kml"));
map.addOverlay(new GGeoXml("http://s/2.kml"));