Disagree with the advice here....
If you have the 18-55 already then there is absolutely zero point in getting an 18-70. You can make up the difference in focal length by stepping a few feet forward or back.
Also, while the 55-200 does feel cheap and plasticy (it is cheap and, well, made of plastic) mr Johns comments are completely hyperbolic. I have zero complaints with the lenses optical quality, and have witnessed none of his complaints as to sharpness and colour casts.
Shots I have taken with the 55-200VR:
Gibson Colour by
bulliver, on Flickr
Reflecting by
bulliver, on Flickr
Towers by
bulliver, on Flickr
Harbin Gate by
bulliver, on Flickr
Dogs by
bulliver, on Flickr
Cree Dancers by
bulliver, on Flickr
No, it is not the best lens on earth, but for it's low cost, I think it is a great value.