I'm working on my ongoing wishlist and I want a good wide-angle lens (see my sig line for the lenses I have) for my Canon Digital Rebel XT. From what I've seen, I have two options: ~ Canon EF-S 10-22 mm f/3.5-4.5 ($690) ~ Sigma EX DC HSM 10-20 mm f/4-5.6 ($500) Obviously, the Sigma looks like the more likely choice if anyone's going to get me one. My questions are two-fold - (1) is the Sigma lens worse than the Canon? and (2) is there a good wide-angle lens that I overlooked? Thanks!