I also want to add to mine:

Kombucha. It is a drink made of fermented tea and sugar from ancient Chinese medicine that was used to detoxify the body. It has yeast and bacteria cultures in it that are good for your body and are said to help with certain ailments.

I have learned to brew and ferment my own after deciding buying it was way too expensive for about $4-$6 for a 20oz bottle. I drink 4-8 oz a day. It has helped me cut back on caffeine as it is a natural source of energy. Also it has helped clear my skin (PMS breakout) and cut back on so much snacking (again, thank you PMS). I also believe it has decreased my back pain due to the glucosamines in it that help with any pre-osteoarthritis in my spine (thanks to 8 years of hardcore competitive cheerleading along with gymnastics and lacrosse).

It really is a panacea.

Just don't let it ferment too long! It could turn alcoholic and that would not necessarily be too good considering being drunk in public is not good and the fact that I, personally, am under 21.