Today I will describe how to take a photo in android application using the built in camera. The way to do it is to simply start ‘activity for result’ instead of simple ‘activity’ and specify android camera application as our activity.
Then, once a picture is taken with a nice built in camera application, we can get it back in our app for further processing:

Main activity class:

package com.softwarepassion.androcamera;

import android.app.Activity;
import android.content.ContentValues;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

public class AndroCamera extends Activity {
    private static final int IMAGE_CAPTURE = 0;
    private Button startBtn;
    private Uri imageUri;
    private ImageView imageView;

    /** Called when the activity is first created.
     *  sets the content and gets the references to
     *  the basic widgets on the screen like
     *  {@code Button} or {@link ImageView}
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        imageView = (ImageView)findViewById(R.id.img);
        startBtn = (Button) findViewById(R.id.startBtn);
        startBtn.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                startCamera();
            }
        });
    }

    public void startCamera() {
        Log.d("ANDRO_CAMERA", "Starting camera on the phone...");
        String fileName = "testphoto.jpg";
        ContentValues values = new ContentValues();
        values.put(MediaStore.Images.Media.TITLE, fileName);
        values.put(MediaStore.Images.Media.DESCRIPTION,
                "Image capture by camera");
        values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");
        imageUri = getContentResolver().insert(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
        intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1);
        startActivityForResult(intent, IMAGE_CAPTURE);
    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == IMAGE_CAPTURE) {
            if (resultCode == RESULT_OK){
                Log.d("ANDRO_CAMERA","Picture taken!!!");
                imageView.setImageURI(imageUri);
            }
        }
    }
}

and layout xml (main.xml):

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:orientation="vertical"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   >
<Button android:text="Start Camera"
    android:id="@+id/startBtn"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">
</Button>
<ImageView android:id="@+id/img"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
</ImageView>
</LinearLayout>