Shooting Notes: I have both the 18-200mm and 55-200mm AFS Nikkors and between the two I really prefer the 55-200mm lens for images with shallow depth of field. The reason is the wonderful, creamy bokeh (rendering of out-of-focus elements) of the 55-200mm lens. For a relatively inexpensive, "plastic" lens, the 55-200mm does a good job in terms of sharpness and is quite acceptable for my purposes. Most (if not all) of the shots taken with the D60 camera where with the onboard flash reduced to -3 EV.
Why two lenses with similar zoom ranges? I purchased the 55-200mm lens as a travel lens for an extended vacation where I wanted to travel with as little bulk as possible. The 55-200mm weighs 40% less than the 18-200mm, and is considerably smaller. That makes a difference when you're wearing a camera around your neck for hours on end! I also wanted to avoid the attention that a larger lens might have generated, and in the event of theft, the 55-200mm would be less of a loss.