This is a teensy, tiny little habit. It takes me about 4 seconds a day, and most of that is the time my digital scale takes to boot up. But it's been amazingly successful for me. I've maintained my weight within the same range (actually, within about 5 pounds) ever since I started the chart. I started the chart originally to lose weight after childbirth, along with counting calories. And then I just kept on going with it after I lost the weight.
I know some people feel that weighing yourself weekly or even less is the best thing to do. They believe that daily weighing just distracts you, and potentially makes you discouraged.
I disagree. I think daily weighing focuses you, and gives you that daily feedback that makes you think twice before you overindulge. It reminds me of when I first got a digital camera. Being able to instantly see the picture I took improved my photography skills tremendously. The feedback of weighing yourself daily is the same - perhaps not quite as instant, but within 24 hours of less, you will get a number that tells you, roughly, how you're doing.