Agree with Sarah, about drinking a glass of water and finding something to do, to keep me occupied. It's particularly good if it's something like knitting that keeps my hands busy. And I no longer watch the Food Network in the evening-- all those pictures of food just make me want to eat!
I try to fill up with lots of vegetables at supper, all the non-starchy stuff. And I try to keep cut-up raw vegetables in the fridge, for when I feel like I just HAVE to have something to eat.