Miracle Fruit

A dude in my office got this Miracle Fruit for Christmas. He said after eating the small berries you can eat sour foods and they actually taste sweet!! Check out the Wikipedia description below, I'll get his reaction for you if you don't try them out yourself!

The Miracle Fruit plant (Synsepalum dulcificum) produces berries that, when eaten, cause bitter and sour foods (such as lemons and limes) consumed later to taste sweet. The berry, also known as Miracle Berry, Magic Berry, Miraculous Berry or Flavour Berry was first documented by explorer Chevalier des Marchaiswho searched for many different fruits during a 1725 excursion to its native West Africa. Marchais noticed that local tribes picked the berry from shrubs and chewed it before meals. . It is an evergreen plant that produces small red berries, with flowers that are white and which are produced for many months of the year. The seeds are about the size of coffee beans.
When the fleshy part of the fruit is eaten, molecules binds to the tongue's taste buds, causing bitter and sour foods to taste sweet. While the exact cause for this change is unknown, one hypothesis is that the effect may be caused if miraculin works by distorting the shape of sweetness receptors "so that they become responsive to acids, instead of sugar and other sweet things". This effect lasts between thirty minutes and two hours.