our favorite less-expensive dining tip at wdw is to have only two meals a day... we tend to bring snacky stuff for a quick early in-room breakfast (i.e. pop tarts, krispie treats, nutrigrain bars) and then have "brunch" at the parks (last breakfast seating) w/maybe a snack late day if we're feeling hungry (ice cream, popcorn, etc) followed by dinner...
if you're in animal kingdom, their "meal deal" is a good bargain because for a little more than the price of just the meal, you get a coupon for a snack and a drink to be used later anywhere in the park!
also, if you are planning to go to planet hollywood, check w/your resort front desk, they often have free appetizer coupons!
other ideas can be found on the budget board... those posters are great w/tips and ways to save before and while you are at wdw!