I am a total lens noob, so maybe any answer to this should be prefaced by a link to a site or thread that adequately explains the basics of lenses. Namely, why some cost $1000+ while others with nearly the same specs cost $150. Anyhow, Last year I bought a Nikon D40 with Nikkor 18-55 3.5 kit lens. I recently upgraded to a D90, but kept the 18-55. I'm realizing that it's probably time to get a lens that complements awesomeness of the D90 with real crispness and sharpness, which the 18-55 seems to lack. What lens options will give me the most bang for the buck in the ~$300 range? Also, and slightly unrelated, how do "macro" lenses work? Do you use them only for closeup stuff or can you use a macro lens as a walkabout lens taking pictures of buildings, people, etc? (and did I use "walkabout" right there?) Any help you guys can provide would be most appreciated.