Get altitude by longitude and latitude in Android

Is there a quick and efficient way to get altitude (elevation) by longitude and latitude on the Android platform?

My approach is to use USGS Elevation Query Web Service:

private double getAltitude(Double longitude, Double latitude) {
    double result = Double.NaN;
    HttpClient httpClient = new DefaultHttpClient();
    HttpContext localContext = new BasicHttpContext();
    String url = "http://gisdata.usgs.gov/"
            + "xmlwebservices2/elevation_service.asmx/"
            + "getElevation?X_Value=" + String.valueOf(longitude)
            + "&Y_Value=" + String.valueOf(latitude)
            + "&Elevation_Units=METERS&Source_Layer=-1&Elevation_Only=true";
    HttpGet httpGet = new HttpGet(url);
    try {
        HttpResponse response = httpClient.execute(httpGet, localContext);
        HttpEntity entity = response.getEntity();
        if (entity != null) {
            InputStream instream = entity.getContent();
            int r = -1;
            StringBuffer respStr = new StringBuffer();
            while ((r = instream.read()) != -1)
                respStr.append((char) r);
            String tagOpen = "<double>";
            String tagClose = "</double>";
            if (respStr.indexOf(tagOpen) != -1) {
                int start = respStr.indexOf(tagOpen) + tagOpen.length();
                int end = respStr.indexOf(tagClose);
                String value = respStr.substring(start, end);
                result = Double.parseDouble(value);
            }
            instream.close();
        }
    } catch (ClientProtocolException e) {} 
    catch (IOException e) {}
    return result;
}

And example of use (right in HelloMapView class):

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        linearLayout = (LinearLayout) findViewById(R.id.zoomview);
        mapView = (MapView) findViewById(R.id.mapview);
        mZoom = (ZoomControls) mapView.getZoomControls();
        linearLayout.addView(mZoom);
        mapView.setOnTouchListener(new OnTouchListener() {
            public boolean onTouch(View v, MotionEvent event) {
                if (event.getAction() == 1) {
                    final GeoPoint p = mapView.getProjection().fromPixels(
                            (int) event.getX(), (int) event.getY());
                    final StringBuilder msg = new StringBuilder();
                    new Thread(new Runnable() {
                        public void run() {
                            final double lon = p.getLongitudeE6() / 1E6;
                            final double lat = p.getLatitudeE6() / 1E6;
                            final double alt = getAltitude(lon, lat);
                            msg.append("Lon: ");
                            msg.append(lon);
                            msg.append(" Lat: ");
                            msg.append(lat);
                            msg.append(" Alt: ");
                            msg.append(alt);
                        }
                    }).run();
                    Toast.makeText(getBaseContext(), msg, Toast.LENGTH_SHORT)
                            .show();
                }
                return false;
            }
        });
    }

You can also use the Google Elevation API. The online documentation for it is located at: https://developers.google.com/maps/documentation/elevation/

Please note the following from the above API page:

Usage Limits: Use of the Google Geocoding API is subject to a query limit of 2,500 geolocation requests per day. (User of Google Maps API Premier may perform up to 100,000 requests per day.) This limit is enforced to prevent abuse and/or repurposing of the Geocoding API, and this limit may be changed in the future without notice. Additionally, we enforce a request rate limit to prevent abuse of the service. If you exceed the 24-hour limit or otherwise abuse the service, the Geocoding API may stop working for you temporarily. If you continue to exceed this limit, your access to the Geocoding API may be blocked. Note: the Geocoding API may only be used in conjunction with a Google map; geocoding results without displaying them on a map is prohibited. For complete details on allowed usage, consult the Maps API Terms of Service License Restrictions.

Altering Max Gontar's code above for the Google API gives the following, with the returned elevation given in feet:

private double getElevationFromGoogleMaps(double longitude, double latitude) {
        double result = Double.NaN;
        HttpClient httpClient = new DefaultHttpClient();
        HttpContext localContext = new BasicHttpContext();
        String url = "http://maps.googleapis.com/maps/api/elevation/"
                + "xml?locations=" + String.valueOf(latitude)
                + "," + String.valueOf(longitude)
                + "&sensor=true";
        HttpGet httpGet = new HttpGet(url);
        try {
            HttpResponse response = httpClient.execute(httpGet, localContext);
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                InputStream instream = entity.getContent();
                int r = -1;
                StringBuffer respStr = new StringBuffer();
                while ((r = instream.read()) != -1)
                    respStr.append((char) r);
                String tagOpen = "<elevation>";
                String tagClose = "</elevation>";
                if (respStr.indexOf(tagOpen) != -1) {
                    int start = respStr.indexOf(tagOpen) + tagOpen.length();
                    int end = respStr.indexOf(tagClose);
                    String value = respStr.substring(start, end);
                    result = (double)(Double.parseDouble(value)*3.2808399); // convert from meters to feet
                }
                instream.close();
            }
        } catch (ClientProtocolException e) {} 
        catch (IOException e) {}

        return result;
    }