Diatomaceous Earth - any good?

recently i read about diatomaceous earth and how it's supposed to do a wonderful multitude of things from lowering cholesterol to boosting metabolism to making you feel better on so many levels. i know it's also good for animals to help prevent intestinal parasites, so i'm trying to find more information there for my horses, dogs, and cats. overall it sounds great, but i can't find any real studies on it, so wanted to see who had tried it, used it, or had any experience with it?

thanks!