I drink a gallon of water every day. I've been doing this for almost a year and I feel so great because of it. I have 4 liter size bottles and I fill them up every night and space drinking them throughout the day. I down one within a half hour of waking up, another before lunch, one before dinner, and one after dinner. Done by 7:00 pm (kids bedtime), then I have time for my 1 cup of milk (hot chocolate).
Because my kids see me drinking the water, they drink theirs also. It's a great way to stay healthy.