One thing I noticed about the D40's kit lens ... I was playing around with it under very dim light, focusing at the ashtray. I kept getting closer until about 3 - 4 inches, and it was still auto-focusing and locking well on the target, in very dim light without hunting !
Took several shots, and great. IMHO, this is a very good lens (for the price) that can pose as a macro lens too, beats the 18-200 in this aspect. Even the 17-35 f2/8 can't get this close, and the 105mm VR had to hunt in less than ideal lighting.