dSLR "skin" - anybody have this? Is it worth it?

I'm about to make my first trip with a dSLR as opposed to my point-and-shoot. I have a cross body strap for comfort but was looking at a kind of "skin" they sell. I have only seen it online, its not in-store. Has anyone used such a product? Does it protect the camera at all or is it money down the drain? By the looks of it the camera would be functional with the skin on, except for changing batteries or memory cards. Thanks in advance for any input.