Hello mates, I've got a serious problem with my GPS on my Nexus One: I wrote a kind of hello world with GPS, but the Toast that should be displayed isn't :(

I don't know what I'm doing wrong...maybe you could help me getting this work. Here's my code:

package gps.test;

import android.app.Activity;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.Toast;

public class GPS extends Activity {
private LocationManager lm;
private LocationListener locationListener;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    // ---use the LocationManager class to obtain GPS locations---
    lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

    locationListener = new MyLocationListener();

    lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 100, 1,
            locationListener);
}

private class MyLocationListener implements LocationListener {
    @Override
    public void onLocationChanged(Location loc) {
        if (loc != null) {
            Toast.makeText(
                    getBaseContext(),
                    "Location changed : Lat: " + loc.getLatitude()
                            + " Lng: " + loc.getLongitude(),
                    Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    public void onProviderDisabled(String provider) {
        // TODO Auto-generated method stub
    }

    @Override
    public void onProviderEnabled(String provider) {
        // TODO Auto-generated method stub
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub
    }
}
}

Theoretically there should be a new toast every 100 milliseconds, shouldn't it? Or at least, when I change my position by one meter!? I've no idea why it doesn't. I must admit I'm new to the topic, maybe I've missed something?

It would be great if you could give me a hint :)

nice greetings, poeschlorn