iLifeTouch has introduced Drink More Water 1.1 (http://ilifetouch.com/DrinkMoreWater) in the Mac App Store. It requires Mac OS X 10.6.6 or later, costs US$1.99 and is found in the Health & Fitness section.

Drink More Water allows you to keep track of exactly how much water you have consumed in a day. It also allows you to keep track of your water consumption for the entire week and provides you with your weekly average.