When I first went to the health club and the trainer there said I should drink a gallon of water a day, I actually laughed at her, I thought she was joking! But now,I won't say that I get a gallon everyday, but, I genereally get at least 100 oz. I had to start out slowly, with 64 oz a day, and work myself up, and I still have to run to the restroom about every 60-90 minutes (luckily at my job they don't care LOL) but I just kept slowly drinking more and more, and now if I only get 64 oz, I can tell. It also helped that I cut out soda, and now only drink a cup of coffee, water and a large glass of milk everyday. I keep a 1 liter water bottle with me at all times, and I fill it from the drinking fountain, or faucet. It is to the point now, that I even take it shopping with me, and I feel like have forgotten something all day when I don't have it.
Just start out slowly, and let your body get adjusted to it, if you keep a bottle with you and just sip it al day long, you'll be amazed at how much you actually drink. You'll see that over time, it gets easier and easier!
Good Luck!
Nicole