I read about this in an article, Anna Nichole Smith used to do this before she had a photo shoot. And I'm sure many other stars have used this little trick too!
All you need is some 35% Food Grade Hydrogen Peroxide. (There are many kinds of hydrogen peroxide, make sure it is this kind!) You can order it online. (That is the only downfall to this trick, is that not very many places carry this product.)
This is a great product for Makeup Artists to carry around in their kit! It is also good for models, or anyone who is photographed regularly. And why not brides, too!! Or anyone who just wants to brighten up their smile!
All you need to do is saturate a cotton ball or Q-tip with the 35% food grade hydrogen peroxide and rub over each tooth. Let this stay on your teeth for about 5-10 minutes, and then rinse your mouth well. Your teeth will be noticeably whiter!