This is just in the news out here in California, since the law took effect July 1.
Weighing California's restaurant calorie-listing law
Requires: "... restaurants in California with 20 or more locations to provide brochures with nutritional information by July 1, 2009..."
The New York City law:
Fed court upholds New York City's calorie-posting rule
"...requires chain restaurants with 15 or more establishments nationally to prominently display calorie content..."
For instance, out here we have California Pizza Kitchen, and while I don't know if they did this before I know they at least haven't done it a long time. Their calories counts, shown at this link, also appear on their menu. (At least the items I looked through on the menu.)