Duncan Louttit wrote

There is another rule that could cause problems to the judges. The prize for the smallest mouse calls for measuring the height, width and length of the mouse (excluding flag!). This could be quite difficult to measure without the judge handling the mouse. As mice can be quite fragile, I am reluctant to have a rule that could result in a judge rendering a mouse incapable of competeing!

As an alternative, I propose that the prize be given to the lightest mouse. The effect of this is similar to smallest mouse and can be measured by the contestant placing the mouse on a scale. There is no problem in measuring weight to a resolution of 1gram or so and the judges need not touch the mouse at all.

Jerry Niman wrote

This gets my vote, I happened to be thinking along the same lines over the weekend, imagining trying to measure the dimensions of each mouse. I also concluded that weighing would be quicker and more argument-proof.

In the spirit of Bill Marshall's contribution, we should specify whether the mouse is weighed fully charged or not (all those electrons...)