Here is a full example of building a camera app in Android that was taken from the Google tutorial.This is the complete tested camera code all in one place with no errors. There was a few errors i got from copying and pasting the code from the Google tutorial but they are fixed in this example. I also added code to display the last image taken so the user can open the picture in a image viewer. I removed excess code without testing so comment if you are having issues so I can make corrections.

This is image for an application I created so the layout below will not include the text, ads or shutter image. Check out my app in the Google Market. 

CameraActivity

public class CameraActivity extends Activity{

    private static Camera mCamera;
    private static CameraPreview mPreview;

    static final int MEDIA_TYPE_IMAGE = 1;

    static Context context;

    /** setting last image taken **/
    static ImageView myImage;
    static File imgFile = null; 
    int duration = Toast.LENGTH_LONG;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.camera_preview);

        mCamera = getCameraInstance();

        context = getApplicationContext();
        // Create our Preview view and set it as the content of our activity.
        mPreview = new CameraPreview(this, mCamera);
        FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
        preview.addView(mPreview);

        myImage = (ImageView) findViewById(R.id.lastPic);
        /** if last image is clicked it will open in an image viewer app **/
        myImage.setOnTouchListener(new OnTouchListener() {
			@Override
			public boolean onTouch(View v, MotionEvent event) {

				Intent intent = new Intent();
				intent.setAction(Intent.ACTION_VIEW);
				if(imgFile == null){
					 CharSequence text = "This is only an icon, take a photo"; 
                 	 Toast toast = Toast.makeText(context, text, duration);
                 	 toast.show();
				}
				else{
				intent.setDataAndType(Uri.parse("file://" +  imgFile.getAbsolutePath()), "image/*");
				startActivity(intent);
				}
				return false;
			}
        });

	/** A safe way to get an instance of the Camera object. */
	public static Camera getCameraInstance(){
	    Camera c = null;
	    try {
	        c = Camera.open(); // attempt to get a Camera instance
	    }
	    catch (Exception e){
	        // Camera is not available (in use or does not exist)
	    }
	    return c; // returns null if camera is unavailable
	}

	public void takePhoto(View v){
        mCamera.takePicture(null, null, mPicture);
	}

	private PictureCallback mPicture = new PictureCallback() {

	    @Override
	    public void onPictureTaken(byte[] data, Camera camera) {
	        File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);

	        if (pictureFile == null){
	            Log.d("ERROR", "Error creating media file, check storage permissions:" );
	        }

	        try {
	            FileOutputStream fos = new FileOutputStream(pictureFile);
	            fos.write(data);
	            fos.close();

	        } catch (FileNotFoundException e) {
	            Log.d("ERROR", "File not found: " + e.getMessage());
	        } catch (IOException e) {
	            Log.d("ERROR", "Error accessing file: " + e.getMessage());
	        }
	        setImage();

	        mCamera.startPreview();
	    }
	};

	/** Create a File for saving an image or video */
	private static File getOutputMediaFile(int type){

        Boolean isSDPresent = android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);
        if(!isSDPresent)
        {	
        	int duration = Toast.LENGTH_LONG;

        	Toast toast = Toast.makeText(context, "card not mounted", duration);
        	toast.show();

        	Log.d("ERROR", "Card not mounted");
        }
	    File mediaStorageDir = new File(Environment.getExternalStorageDirectory().getPath() + "/cameraSpeed/");

	    if (! mediaStorageDir.exists()){
	        if (! mediaStorageDir.mkdirs()){

	            Log.d("MyCameraApp", "failed to create directory");
	            return null;
	        }
	    }

	    // Create a media file name
	    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
	    File mediaFile;
	    if (type == MEDIA_TYPE_IMAGE){
	        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
	        "IMG_"+ timeStamp + ".jpg");
	        imgFile = mediaFile;
	    } else {
	        return null;
	    }

	    return mediaFile;
	}

	public static void setImage(){
          if(imgFile !=null){
	        if(imgFile.exists()){
		    Bitmap myBitmap = decodeSampleImage(imgFile, 100, 100); // prevents memory out of memory exception
	            myImage.setImageBitmap(myBitmap);
	        }
          }
	}

    @Override
    protected void onPause() {
        super.onPause();
        releaseCamera();              // release the camera immediately on pause event
    }

    @Override
    protected void onResume() {
        super.onResume();  
        if(mCamera == null){
        mCamera = getCameraInstance();

        context = getApplicationContext();
        mPreview = new CameraPreview(this, mCamera);
        FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
        preview.addView(mPreview);
        }
    }

    private void releaseCamera(){
        if (mCamera != null){
            mPreview.getHolder().removeCallback(mPreview);
            mCamera.release();
            mCamera = null;

        }
    }

    public static Bitmap decodeSampleImage(File f, int width, int height) { 	    
        try { 	        
             System.gc(); // First of all free some memory 	        // Decode image size 	        
             BitmapFactory.Options o = new BitmapFactory.Options(); 	        
              o.inJustDecodeBounds = true; 	        
              BitmapFactory.decodeStream(new FileInputStream(f), null, o); 	        // The new size we want to scale to 	                            final int requiredWidth = width; 	        
final int requiredHeight = height; 	        // Find the scale value (as a power of 2) 	        
int sampleScaleSize = 1; 	        
while (o.outWidth / sampleScaleSize / 2 >= requiredWidth && o.outHeight / sampleScaleSize / 2 >= requiredHeight)
	            sampleScaleSize *= 2;

	        // Decode with inSampleSize

	        BitmapFactory.Options o2 = new BitmapFactory.Options();
	        o2.inSampleSize = sampleScaleSize;

	        return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
	    } catch (Exception e) {
	      //  Log.d(TAG, e.getMessage()); // We don't want the application to just throw an exception
	    }

	    return null;
	}
}

CameraPreview

package com.nathanhaze.speedcamera;

import java.io.IOException;

import android.content.Context;
import android.graphics.Canvas;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

/** A basic Camera preview class */
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
    private SurfaceHolder mHolder;
    private Camera mCamera;
    private GlobalVar  gv = new GlobalVar();

    public CameraPreview(Context context, Camera camera) {
        super(context);
        mCamera = camera;

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
        // deprecated setting, but required on Android versions prior to 3.0
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, now tell the camera where to draw the preview.
        try {
        //	setWillNotDraw(false); 
            mCamera.setPreviewDisplay(holder);
            mCamera.startPreview();
        } catch (IOException e) {
            Log.d("ERROR", "Error setting camera preview: " + e.getMessage());
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
    //	Paint temp = gv.getPaint();
    //	temp.setTextSize(150);
  	  //  canvas.drawText(Integer.toString(gv.getSpeed()), 50, 100, gv.getPaint());
        Log.w(this.getClass().getName(), "On Draw Called");
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // empty. Take care of releasing the Camera preview in your activity.
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // If your preview can change or rotate, take care of those events here.
        // Make sure to stop the preview before resizing or reformatting it.

        if (mHolder.getSurface() == null){
          // preview surface does not exist
          return;
        }

        // stop preview before making changes
        try {
            mCamera.stopPreview();
        } catch (Exception e){
          // ignore: tried to stop a non-existent preview
        }

        // set preview size and make any resize, rotate or
        // reformatting changes here

        // start preview with new settings
        try {
            mCamera.setPreviewDisplay(mHolder);
            mCamera.startPreview();

        } catch (Exception e){
            Log.d("ERROR", "Error starting camera preview: " + e.getMessage());
        }
    }
}

PhotoHandler

import java.io.File;
import java.io.FileOutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;

import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Environment;
import android.widget.Toast;

public class PhotoHandler implements PictureCallback {

  private final Context context;

  public PhotoHandler(Context context) {
    this.context = context;
  }

  @Override
  public void onPictureTaken(byte[] data, Camera camera) {

    File pictureFileDir = getDir();

    if (!pictureFileDir.exists() && !pictureFileDir.mkdirs()) {

     // Log.d(MakePhotoActivity.DEBUG_TAG, "Can't create directory to save image.");
      Toast.makeText(context, "Can't create directory to save image.",
          Toast.LENGTH_LONG).show();
      return;

    }

    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyymmddhhmmss");
    String date = dateFormat.format(new Date());
    String photoFile = "Picture_" + date + ".jpg";

    String filename = pictureFileDir.getPath() + File.separator + photoFile;

    File pictureFile = new File(filename);

    try {
      FileOutputStream fos = new FileOutputStream(pictureFile);
      fos.write(data);
      fos.close();
      Toast.makeText(context, "New Image saved:" + photoFile,
          Toast.LENGTH_LONG).show();
    } catch (Exception error) {
   //   Log.d(MakePhotoActivity.DEBUG_TAG, "File" + filename + "not saved: "
     //     + error.getMessage());
      Toast.makeText(context, "Image could not be saved.",
          Toast.LENGTH_LONG).show();
    }
  }

  private File getDir() {
    File sdDir = Environment
      .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
    return new File(sdDir, "CameraAPIDemo");
  }
}

Manifest

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.nathanhaze.speedcamera"
    android:versionCode="3"
    android:versionName="1.2" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_SETTINGS" />

    <uses-feature android:name="android.hardware.camera" /]>
    <uses-feature android:name="android.hardware.camera.autofocus" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@android:style/Theme.NoTitleBar" >
        <activity
            android:name="com.nathanhaze.speedcamera.CameraActivity"
            android:screenOrientation="landscape">
          <intent-filter>
       		   <action android:name="android.intent.action.MAIN" />
     		   <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
        </activity>
    </application>

</manifest>

Layout

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

         <FrameLayout
            android:id="@+id/camera_preview"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_weight="1" >

         </FrameLayout>

   <LinearLayout
      android:id="@+id/speedBackgound"
      android:layout_width="fill_parent"
      android:layout_height="80dp"
      android:layout_gravity="bottom"
      android:orientation="horizontal" >

       <ImageView
          android:id="@+id/lastPic"
          android:layout_width="70dp"
          android:layout_height="70dp"
          android:layout_gravity="center"
          android:layout_marginLeft="10dp"
          android:layout_weight="1" />

       <Button
          android:layout_marginLeft="10dp"
          android:id="@+id/button_capture"
          android:layout_width="80dp"
          android:layout_height="80dp"
          android:onClick="takePhoto" 
          android:layout_gravity="right"/>
   </LinearLayout>

 </LinearLayout>