Another negative vote for the D40 because of the lens options. Get a used D50 or D70s instead.
### I have a different opinion. The 18-55 kit lense that comes with the D40 is outstanding for a "kit lense"...far superior to Canon's kit lense...and I like Canon gear btw. Also, the Nikon 18-200 VR ($750) is just out of this world in terms of value. Nikon was lagging behind Canon there for a while....not any more...which is good for both camps imo.
Good resources:
www.bythom.com/
kenrockwell.com
dpreview.com