I took these shots looking into a mirror so that's why things look flipped around. I wanted to do this so I could show the new battery grip I got for my D200 about a week ago. The grip itself is that extension along the bottom portion of the camera below my hand. If you looks carefully, you can almost see the seam between the camera body and the grip. It's screws right into the bottom of the camera via a plastic command dial just below the lens. The grip holds an additional battery so it gives you twice the shooting time. It also adds some additional weight to the camera which will be nice when I get a couple bigger lenses this summer. Soon as I can save up enough cash.
Another benefit of the grip is that it contains a second shutter release. This enables you to turn the camera sideways to take a vertical picture while still holding the camera in a comfortable manner. Very handy. If you have a DSLR, I would highly recommend picking up one of these grips. 9 times out of 10, there's a grip for your specific camera, you just gotta look online for it. Not to mention, they just look badass...and I'm all about the badassness.