At 03:58 PM 1/3/2006, you wrote:
As far as grounds in-between lines, you don't always need that, if you have a group of signals that change together then they can be grouped together without interference, clocks though need to be kept away from control or data signals.
Note that you don't have to ground every other line for shielding and also have power distribution lines. The power lines should be so well bypassed that they can be considered RF ground potential and used for shielding also. Thus every other line can be ground or power, and the other half signals.John