private async void GetPhotos()
 {
     try
     {
         StartBusiness();
         Photos = new ObservableCollection <PicasaItem>(await SocialNetworkService.GetPhotosAsync(UserId, AlbumId));
     }
     catch (Exception ex)
     {
         Log.Write(string.Format("GetPhotos Error: {0}", ex.Message));
         throw;
     }
     finally
     {
         StopBusiness();
     }
 }