Here is a nice, very informative review of two probably most popular modern Nikon kit-lenses: http://goo.gl/4Pdywo
"The Nikon 18-55mm VR
It doesn’t do everything, this one. Zoom range is limited, there is no instant focus override. It is a simple, light, cheap lens with vibration reduction. Doesn’t promise you the world. But it does what it does very well. It is a brilliant little lens.
The Nikon 18-105mm VR
This one promises a bit more. Double the zoom range. Instant focus override. Looks a bit more serious as well. In the end: the niggles take a lot of the fun away from this lens. On paper, this is a much better lens, shame that it doesn’t work as well in the real world.
So, which one am I keeping?
Despite the 18-105 having double the zoom range, I always find myself using the 18-55VR. As I said, it is a lot more fun"
Like I wrote in my previous post, there is a problem with the built of a 18-105, in terms of that rubber isolation laying between inner tube (barrel that contains the glass elements) and the outer barrel tends to "crawl out" of it's place, so to speak - I saw with my own eyes two such lenses in just a couple of months. Both lenses were (are) brand new ones, purchased with the brand new cameras.
Here is a bunch of people complaining of the 18-105's bayonet being too prone to breaking, which is not so common with other plasticky lenses (though is possible, of course): http://goo.gl/z4sNlG