I'm not surprised by tealdy's response. It's a fad diets. Fad diets tend to have the same endings. A bit of fast weight loss, then some weight gain, then frustration on the part of the dieter.
As far as fad diets go Special K is certainly not the worst one out there. However, it does not compare to what eating healthy, natural, unprocessed foods and consistent exercise will do for you.
The Special K diet is nothing more than a decreased calorie diet. Any meal plan that reduces calorie intake will promote weight loss. The Special K concept is a temporary and is realistic for long term success.
friend tried this diet. she ended up losing about 15 pounds in about 2 months but found it extremely hard to stick to. i'm sure you can get the same results through eating low calorie meals, and would have more variety to your food!