The Shake Weight

Okay, so the other day my friend and I were talking about the Shake Weight.  I don't know much about it nor have I really heard anyone speaking on it a great deal.  I am a research person so I will definitely get on the Internet and Google away.  After reading the pros and cons, the cons will definitely make me second guess as to whether this is a product I would want to invest in.  Has anyone ever used this product?  If so, I would like to hear your opinion on it.