I know this gets asked all the time...but I'm just dying here. I've looked at the same lenses over and over and over, but I just can't decide! Right now I only have my Canon XTi's kit lens (18-55mm F3.5-5.6), and the 50mm 1.8....no speedlight or anything. I desperately want a good walk around lens and I'm stuck. I'm leaving in 2 weeks for a vacation in Texas and want the new lens by then. Sadly, my interests are everything...I expect that I'll want to do both macro-ish shots as well as fairly wide landscapes. I keep saying...well, if I need the 18mm I can always use the kit...and if I need the 2.8 I can always use the 50mm and my brain keeps tossing between all the choices. I'm considering the following: Tamron 28-75mm f2.8 XR Di LD - Pleased with the maximum ap but concerned that it won't be wide enough...also, will it shoot decent flowers for a walk-around. Canon EF-S 17-85mm f/4-5.6 Image Stabilized USM SLR Lens - Pleased with the range, but concerned with the maximum ap and macro capabilities. Sigma 17-70mm f/2.8-4.5 DC IF Macro Lens - Fairly pleased with the range (I think) and macro capabilities, but concerned with the quality and changing aperture. I welcome all thoughts, opinions, suggestions. My price range is below $600.