If you haven’t tried miracle fruit before, you should. Per the Wikipedia entry, “It contains a glycoprotein molecule, with some trailing carbohydrate chains, called miraculin. When the fleshy part of the fruit is eaten, this molecule binds to the tongue’s taste buds, causing sour foods to taste sweet.”
I threw a miracle fruit party a week ago, and sure enough, you can drink balsamic vinegar straight and even delight in eating lemons and limes. Sour cream tastes like Greek yogurt sweetened with sugar.
For a full report on the experience–including advice on hosting your own party–see my friend Patrick’s blog post.