This is to go along with my journal goal, too. Wish me luck, because I read that drinking more water will help me feel better and more energized, but I'm not completely giving up soda...well, not yet, anways...
Your body weight / 2 = Amount of water needed in ounces.
So... 120/2 = 60 ounces for me, or 7 1/2 cups of water a day.