My sister has done the apple cider thing and recommends it. She says the ACV with the mother is best too. She said the vinegar kills wild yeasts in the digestive tract and that it totally got her over her sugar/refined carb cravings (since yeast eats sugar).
My take on it is that vinegar is good for you and this is one "diet gimmick" or fad or whatever you want to call it that isn't being touted because it's making the pharmaceutical industry a bunch of money, and it's not going to have the FDA deeming it dangerous to your health. It's also very cheap. So if you're curious, why not give it a try? As far as I know, apple cider isn't addictive either.