I'm going on a trip in december to Belize and Cozumel and I'd like to get a new lens for it. Hopefully going to shoot some Mayan ruins down there and other landscape photography. I'm looking for a new lens I can use as a 'walk-around' lens. I really don't do portraits, mainly landscape stuff. My budget is around $500. Right now I have only the 18-55 kit lens. Oh ya, I have the D40x.