A good short guide on eating "out".
The New York Times > Health > Personal Health: On the Road, Avoiding Pitfalls at the Pit Stops
I actually keep a copy of Wendy's, McDonald's, and several other restaurants in the car.
First, I need the carb counts (though they are in my Palm Pilot). But what I really use them for is to compare calories.
By the way -- I count carbs, and try to keep them low AND count calories, and don't worry too much about protein and fat. I also always choose the lower calorie of two items -- sometimes the low-fat is actually higher in calorie than the regular. Sometimes it's the other way. So you have to watch.
By the way, Wendy's has more gotcha's on the menu than McDonald's. I've eaten more calories than I planned at Wendy's than McDonald's.
Also, watch the Wendy's chicken sandwiches, since they "reformulated" them, they changed in carb count and calorie count.