I found these videos that compare the features and handling of the Nikon D700, the Nikon D300 and the Nikon D90. Obviously, all of these cameras are exceptional machines, but there are some differences in the handling of each of them that are worth checking out.
The first video gives a pretty detailed comparison of the functionality of the backs of each of the D700, D300, and D90 cameras.
The second video gives a comparison of the top, side and front of the Nikon D700, D300, and D90 cameras.
