Insertar una imagen en Android

package com.oskratch.titan;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class TitanDesert extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        ImageView portada = (ImageView) findViewById(R.id.imagenPortada);
        portada.setImageResource(R.drawable.portada);
        Button botoPortada = (Button) findViewById(R.id.botoPortada);
        botoPortada.setOnClickListener(new View.OnClickListener() {
o
o@Override
opublic void onClick(View v) {
oIntent about = new Intent(TitanDesert.this, Listado.class);
ostartActivity(about);
o}
o});
    }
}