This example shows you how easily jQuery + jMaps makes adding a ground overlay to your map.
Google ground overlays allows you to add a graphic to a map at a defined position.
jQuery(document).ready(function(){
jQuery('#map1').jmap('init', {'mapType':G_HYBRID_MAP,'mapCenter':[40.736216,-74.193393]});
jQuery('#map1').jmap("AddGroundOverlay", {
'overlaySouthWestBounds': [40.716216,-74.213393],
'overlayNorthEastBounds': [40.765641,-74.139235],
'overlayImage': "http://www.lib.utexas.edu/maps/historical/newark_nj_1922.jpg"
});
});