Here's my outfit: Canon 30D Sigma 10-20mm Sigma 17-35mm Canon 50mm 1.8 Sigma 70-200 2.8 Sigma 1.4x TC As you see, I pretty much got wide and zoom sides covered. But the "walkaround" range has some gaps. 17-35 sometimes just doesn't have enough reach. 50 is a good prime, but no zoom/flexibility. What should I do? Tamron 24-70 gets pretty good reviews. How about Sigma 17-85?? Canon 24-105L or the new Canon 17-55 2.8IS are expensive options. Any thoughts? What's your favorite walkaround lens? Thanks.