Write you names and wedding date on a wood heart and frame it. Have your guests sign smaller hearts and drop them via a small slot on the top. What a cute and unique guest book idea that you can display after your wedding.
Guests throw darts at balloons with paint inside. You keep the art. :) This is such a fun Idea. You choose the colors and the size to coordinate with your style - might be more enduring than having a fingerprint tree in your house forever.