For every trip my family creates a "Disney Box" which is usually just a shoebox covered in construction paper and decorated with Disney pictures. Everyday we throw our spare change or dollar bills (if we're feeling generous!) into the box, and about a week before the trip we sit together and roll up all the change. Also, we make a "Countdown Chain" out of colored construction paper, and rip off a link of the chain everyday until the day we leave. It's a great way to look forward to the trip, and you don't get a chance to forget you're going (not that I'm sure any of us do anyway!