From Treehugger.com
Now that bottled water is no longer a fashion accessory, a lot of companies are adding flavors, vitamins and other enhancements to attract customers, to convince buyers that it is a real drink rather than just plain water. Xin Lu at Wise Bread notes that this is something that you can easily do yourself, and suggests a couple of recipes. Her suggestions include:
1. Salt: This is, in fact, just what Coca-Cola does to tap water to make Dasani—a tiny bit of salt makes it taste better. Xin Lu notes that your body also absorbs it more quickly.
2. Ginger: Good for clearing your throat and sinuses during a cold.
Other ideas include citrus, herbs, berries and “plum wine or umeshu. It is a very sweet Japanese liquere made from green plums.” ::Wise Bread