I think a door knocker and lunch are good ideas. I won't get married for either, but they ARE good ideas!
When my friends got married 12 years ago, I gave them a food gift basket. She is hoity toity when it comes to food, and he isn't. One half was for her, a baby champagne bottle, some brie, maybe a little cheap caviar and crackers or something and some chocolate. His side was Miller Lite, vienna sausages, and Sweet Sue Chicken and Dumplings in a can.