Nikon D40, D 80 or Canon 400D?

color
nikon's color was sharp. canon's color was sofe.

lens
nikon can use their own lens only and canon can use other's lens.

price
400D's function more than D40X
400D's a bit cheaper than D40X in price.
D80 was the most expensive one.but very professional.

if beginner, i recomended to buy 400D or D40X.
if only beginner and not further to professional, canon will be better.

that's my own point of view.
hope that it is helpful. ^_^