navigationItem.rightBarButtonItems

UIBarButtonItem* gamecenterButtonItem, *gamecenterButtonItem2 ;
    {
        UIImage* image1 = [UIImage imageNamed:TEX_GAMECENTER_BTN_1];
        UIImage* image2 = [UIImage imageNamed:TEX_GAMECENTER_BTN_2];

        CGRect frame = CGRectMake(0, 0, image1.size.width, image1.size.height);

        UIButton *gcButton = [[UIButton alloc] initWithFrame:frame];
        [gcButton setBackgroundImage:image1 forState:UIControlStateNormal];
        [gcButton setBackgroundImage:image2 forState:UIControlStateHighlighted];

        gamecenterButtonItem = [[UIBarButtonItem alloc] initWithCustomView:gcButton];
    }

    {
        UIImage* image1 = [UIImage imageNamed:TEX_GAMECENTER_BTN_1];
        UIImage* image2 = [UIImage imageNamed:TEX_GAMECENTER_BTN_2];

        CGRect frame = CGRectMake(30, 0, image1.size.width, image1.size.height);

        UIButton *gcButton = [[UIButton alloc] initWithFrame:frame];
        [gcButton setBackgroundImage:image1 forState:UIControlStateNormal];
        [gcButton setBackgroundImage:image2 forState:UIControlStateHighlighted];

        gamecenterButtonItem2 = [[UIBarButtonItem alloc] initWithCustomView:gcButton];
    }

    self.navigationItem.rightBarButtonItems = [NSArray arrayWithObjects:gamecenterButtonItem, gamecenterButtonItem2, nil];