Productivity blog Dumb Little Man has come up with an interesting way to get your teeth whiter - strawberries and baking soda.
Combined with baking soda, strawberries become a natural tooth-cleanser, buffing away stains from coffee, red wine, and dark sodas. While it's no replacement for a bleaching treatment at your dentist's office, "this is a fast, cheap way to brighten your smile," says Adina Carrel, DMD, a dentist in private practice at Manhattan Dental Arts in New York. "Be careful not to use this too often, though, as the acid could damage the enamel on your teeth."
In the interests of research, I tried this myself. I didn't see any instant results, but it tasted pretty good (better than those nasty whitening strips!) and it's certainly a lot cheaper.