I have to agree with pixelliste. Having changed from a Nikon D200 to a Canon 40D in March, I have absolutely no regrets. IQ is first class - I became increasingly frustrated with the lightly 'veiled' appearance of images from the D200 (which seems to be a characteristic of Nikon DSLRs - I read yesterday that Images from the D300 and D700 appear 'veiled' too). As for ergonomics, I find the Canon more logical to use than the Nikon, something which flies in the face of convention (of course, it could mean that I'm illogical compared with others
). Those who make a living out of studying these things conclude that the IQ of the 40D is better than any of the Rebels, all things being equal. Build is also better and certainly the Rebel would be too small for me to use easily. Good luck with whatever you choose.