One year my parents had plane tickets for a family vacation places inside sealed cans. I don't know how they had this done, but they were literally canned. We got can openers in our stockings and thought that was very strange! I sure would not do that with little kids though, way too sharp. You are getting some great ideas. I had a friend who had to follow a string all through her house to ultimately find a key for a car from her husband! I am sure they will love the gift, I know I would!