But anyhow, the black si only $40 more once you configure the 2.0GHz white one with the same hard drive. If the $40 is worth black then you should get it.
You can buy a 120 GB harddrive for less than Apple charges for it and install it yourself. You often get a longer warranty on the harddrive than on Apples computer, which is another bonus. Plus, you get a 80 GB harddrive to use as a backup drive or something (put it in an enclosure).
This is not possible with the black MacBook, so I'd say that the price difference is bigger than $40, even if you get the same harddrive.