private class RatedCallsContentObserver extends ContentObserver {
	Handler mHandler;
	
	public RatedCallsContentObserver(Handler h) {
		super(h);
		mHandler = h;
	}
	
	@Override
	public boolean deliverSelfNotifications() {
		return true;
	}
	
	@Override
	public void onChange(boolean selfChange) {
		//here is where you handle the call log change
		//it may be a good idea to ensure that the call log application is already running before bringing your app to the foreground
		//to ensure it is displayed on top of the call log app
		
		super.onChange(selfChange);
	}
}


//later in the Service, attach the appropriate content URI to an instance of our observer
this.getApplicationContext().getContentResolver().registerContentObserver(android.provider.CallLog.Calls.CONTENT_URI, true, new RatedCallsContentObserver(internalHandler));