Saving Persistent State

 public class CalendarActivity extends Activity {
     ...

     static final int DAY_VIEW_MODE = 0;
     static final int WEEK_VIEW_MODE = 1;

     private SharedPreferences mPrefs;
     private int mCurViewMode;

     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         SharedPreferences mPrefs = getSharedPreferences();
         mCurViewMode = mPrefs.getInt("view_mode" DAY_VIEW_MODE);
     }

     protected void onPause() {
         super.onPause();
 
         SharedPreferences.Editor ed = mPrefs.edit();
         ed.putInt("view_mode", mCurViewMode);
         ed.commit();
     }
 }