I own an XT and have friends with XTi's and I also know someone who went and bought a Nikon D40 <LOL...yeah, that's you Max>. There are some pretty significant differences between different manufacturers and between the different models (XT Vs XTi). What it comes down to is, what are your requirements ; Megapixels, LCD screen size, frames per second, ir sensors, etc, etc, then how many of them can you get for the price you want to pay. Maybe even trade off some things on that list??
If you're ready to purchase a DSLR and haven't decided on a manufacturer or model, I'd highly recommend writing down a list of "needs" and a list of "wants" then prioritizing these things to help you me make your decision. I ended up buying an XT (body only), and a 100mm Macro lens at the same time. It was more important to me to have a good macro lens right away rather then spend that extra money for a kit lens. I did end up buying a walk-around and zoom lens later, but I was able to start shooting macro's right away and that was better for me at the time.
In a nut shell, when it comes down to the XT, XTi, or D-40, there are difference. When I was researching before I bought my DSLR, I asked this same question in a photog forum and was given some very sound advice. If you do nothing else, make sure to buy the camera that is based on your budget and needs over people's preferences.
Nikon Vs Canon is a lot like Ford Vs Chevy, they both make some great cars but in the end, it's what works best for what you want to do, and how much capability you can afford at the time. Otherwise, we'd all own an EOS-1Ds Mark III's right? LOL
Good Luck, looking forward to seeing some pics soon.
