Whether on a menu or in separately available literature, calorie counts should be readily available to anyone eating in a restaurant. This would be helpful to anyone on a voluntary calorie-restricted diet, but it would also be good for everyone to have an understanding of how many calories they're ingesting. It would also be beneficial to list on the menu (or separate literature) how many calories should be eaten by the average person, so people who are less knowledgeable will be able to see just how calorie restaurant food often is. As our country struggles with just what is making people overweight, requiring calories to be listed only makes sense, and is an easy enough thing to do.
I believe calorie counts on menus should be mandatory. It would greatly help people who are watching weight or calories. I think it would also help obese people realize how much bad stuff and bad calories they are putting into their bodies. If calorie counts were mandatory, the obesity of the USA might go down.