Google Geo-location Service
'1.1.0',
'host' => 'example.com',
'wifi_towers' => array(
array( 'ssid' => 'ZyXEL_3934rar', 'mac_address' => "00:02:CF:E4:60:CE" )
)
);
$c = curl_init();
curl_setopt( $c, CURLOPT_URL, 'https://www.google.com/loc/json' );
curl_setopt( $c, CURLOPT_POST, 1 );
curl_setopt( $c, CURLOPT_POSTFIELDS, json_encode( $request ) );
curl_setopt( $c, CURLOPT_RETURNTRANSFER, true );
var_dump( curl_exec( $c ) );
]]>
http://code.google.com/intl/es-ES/apis/gears/geolocation_network_protocol.html