Robb
Do yourself a favor and find an older AF-D in the 100-200mm range if you want a true macro lens.
Its Nikon glass so it is quality and it will AF on all camera's including the lower end models like the D40; Small, lightweight and portable; Good for someone who want's a normal lens comparable to the 35mm for regular shooting, and may have the need to shoot a quick flower or product like jewelery...
Its focal length is its greatest weakness; No macro hobbyist would ever use anything under 100mm; Lenses like this force you to get really close which: A: Puts you in your own shadow; B: Scares insects away; C: Forces you to use a ring flash or off shoe.