Here's a tip for all you bowlers out there that cannot bowl straight, I guess it's a little on the cheating side, or isn't it? You be the judge.
Hold the wiimote as you normally would. Now move your fingers around so that you position the upper part of the wiimote (slightly below the D-pad) between your forefinger and middlefinger. Push your fingers around the wiimote so that the sides of the wiimote are securely locked between the fingers. You will press the B button with your middle finger. More your fingers around abit so that you can reach the B button and still have the wiimote locked between the fingers. This will make it much easier to swing the remote straight because the weight of the remote is straighter below your hand and because it's locked between the fingers you will not twist it as easily.
Try it, it's much easier bowling straight with this technique! but I'd say it's abit of a cheat!