Couple of months ago a friend of mine told me, that she has been drinking water mixed up with apple cider vinegar and honey to keep herself healthy. Though at first I was a little suspicious about the whole vinegar drinking idea, after a little research I tried it myself. And I have to say - this stuff works. I didn't get any colds throughout the winter season, it gives me energy kick in the morning (which is great, because I don't drink coffee) and on top of that I have lost 5 pound within the first month of using it. Usually I make the drink in the water bottle according to the directions on the bottle and sip on it while at work.
here's the link to their website:
http://www.bragg.com/products/applecidervinegar.html
and this is recipe for the "cocktail":
http://www.bragg.com/bragglifestyle/drinks.html