The d40 is a toy, plain and simple. It just feels cheap in your hands, plus, with the focus motors being located in the lens instead of the body, half of the f-mount glass on the market won't auto focus on the things.
...and, as flightdoc mentioned, they're slow. Very slow. To focus. To shoot. To turn on. Everything.
I'd pass on the d60 as well due to the fact that neither of them have the screen on the top of the body to tell you shutter/f-stop/etc, which I just can't deal with not having. It's absurd to me to get rid of such an integral piece of the camera.
All in all it's obvious that both of them were made for beginners (I wouldn't even say that they're good enough for amateur level photographers) and, coming from a person that pays the bills with his camera gear, the only time I would use one is if I had absolutely no other option.
...I'd save for the XTi over it anyday, and I'm a nikon guy, myself.