Also, the banana peel is actually good for your teeth because it contains minerals and is not acidic. (Brushing your teeth with strawberry pulp damages the enamel because strawberries are too acidic). Also, there is absolutely no pain or sensitivity involved with a banana.
Other at-home whitening remedies which can work is swishing hydrogen peroxide. Hydrogen peroxide is the active ingredient in most teeth whitening products. Be sure to buying the 3% strength, as higher concentrations can burn the skin. You can even dilute the 3% with water (50:50) if you want to. Hydrogen peroxide is also helpful against caries. Avoid swallowing, especially if the hydrogen peroxide you are using is not food grade. Also, don't use for too long non-stop, as the H2O2 wipes out the good bacteria along with the good, and this might lead to a case of black hairy tongue or thrush. So definitely take a pause after using peroxide for a week or two, and definitely don't use more often than once a day. Another way to whiten teeth at home that I know of is baking soda -- I have heard it might be too abrasive, but on the other hand many toothpaste products from organic brands contain baking soda. Does anyone know whether it is ok?
If you prefer a store-bought whitener, the general consensus is that Crest strips are the best thing out there. They can be painful for sensitive teeth though, and using them too often might damage the teeth. I also recall that they have a different name in some countries but I don't remember what it is -- can anyone help me out here?
Lets talk about prevention for a moment -- coffee is the greatest culprit when it comes to teeth stains, so if your teeth colour is important to you you might want to cut down on your coffee intake, as well as that of red wine.
The colour of your lipstick can make your teeth look yellower or whiter. If your teeth are yellow you might want to avoid orange-ish tones, and some bright colours might also make your teeth look even more yellow. This is relative to your skin tone though, so you might have to test things out for yourself.
I heard that Americans are obsessed with perfectly white and straight teeth. Is this true? I personally don't have either perfectly white or even very straight teeth, but I used to have very very crooked ones and it took a long time to get them straight-ish and the process was not entirely painless (my palate was stretched), so I appreciate and like the teeth I have now even they are not perfect.
Is the appearance of your teeth important to you? What do you use to keep them white? Oh, and you might also like my post on tips on keeping your teeth healthy.