If that is what you require from the lens, then the 18-200 sounds like it would suit your needs well Just don't expect the results to blow you out of the water compared to a dedicated wide angle or a dedicated telephoto.

Well technically yes, but 'telephoto' refers to a focal length range, not a type of lens. A Prime will produce the best results. A general rule of thumb is, the longer focal range the lense covers, the poorer the quality will be. This doesn't apply for everything of course, but like i say, general rule of thumb.

What everyone does if they can, have a lens for one thing, and a lens for another. Dedicated lens for landscapes, lots of smaller range zooms, or a collection of primes.

Really it's upto you. I'de love my lens collection to be all primes, but that's far too expensive for most students Zooms are good alternatives, and many are said to be as sharp and fast focusing as primes (Canon 70-200 2.8 L non-IS being a good example), but you still want to try and cover the smallest range possible if you want the best images.

IE rather than a 18-200, i'de probabaly have a 10-22, 24-70 2.8, and a 70-200 2.8. Hella expensive, but the images you get from the dedicated lenses will often far surpass that from the 18-200.

Classic case of Jack of all trades, master of none.

I wanna build up to that once I've got through uni and got some serious money - until then I think the Nikon 18-200 is cool enough - cheers!