Water

Water is a great way to flush out toxins in your body but for the fitness concious ones of you it will keep you active as you're running to the toilet every ten to twenty mintues, also gives your kidneys a good work out not to mention you muscles.

water is also good if you have been drinking too much the night before. it is good at ileviating hang overs.

Hang over - (veisalgia)

describes the sum of unpleasant physiological effects following heavy consumption of alcoholic beverages. The most common reported characteristics of a hangover are headache, nausea, lethargy, sensitivity to light and noise, and thirst *wikapedia

it is also good for staving off inappropriate hunger pangs. sometimes thirst is mistaken for hunger. the rule is if you are still hungry after a pint of water then god mad.