well i own a nikon d40 and i love it.. it takes some nice ass pics and my boy merv has a canon rebel xti it also takes nice ass pics so u cant debate between these two cuz there both great cameras pictures look clear and crisp with both cameras and the reason for me buyin the nikon was #1 to test between the two (both are great)
and #2 cuz my poket was throwing only 700 or less and i payed 609 out the door with a year to year warrenty plan lol but both cameras are great.
And pixel wise the xti is 10.1 mp and mine is 6.1 mp and unless ur makeing posters and billboards u shouldn't worry bout it but good luck with ur choice........jusy keep in mind there both great cameras....