Personally, having played with the Nikons and Owning a Rebel XT. Id get the canon. Though both have different features, and different settings that you might need to really explore before you go all out and purchase.
there are some settings the Nikon has that the Canon SHOULD have. There are some that the Canon has the Nikon dosnt that you WISH it did!
Either way, if you arent advanced at taking pics now, either is a good buy for the money. Look on ebay. ( be sure to check the seller's ratings)
Taken with my Rebel. Played a little in photoshop, but not too much other than cropping and a quick sharpening. * Which all images can use* once i get my hands on a nice Macro lens, the shots i take will be far more impressive.