I've never ceased to hear good things from you guys about Canon's 50mm, but after reading some of the reviews of both these lenses (Sigma's and Canon's), I kind of lean towards the Sigma. I'm interested in macro photography, and the Sigma has a 1:1 ratio. Also, I need a faster "walk around" lens than my current lenses (fastest I have is f/3.5). The Sigma got good reviews in both aspects, and seems like a great combo for the price. Just wondering what you have to say about the Sigma against the Canon... I'll be using it with a 350D, if that matters. Also, I found one (Sigma) on Froogle for $173, and one on ebay for $99 with 2 days left.. (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160009963997&fromMakeTrack=true)<-- says for Nikon, though? I know that's more than what the Canon would cost, but the Sigma seems to have more features. Of course, I'd be going from f/1.8 on the Canon to f/2.8 on the Sigma.. HELP ME CHOOSE!