Really time would be the best gift you could give to anyone. While you can't exactly do that you can and regularly do give your time to someone else. Incidentally, this is the best way to end up with great children. If you spend time with them when they are young, they will spend time with you when you are old.
While we can't actually give time itself we can improve the quality of time we do give. For my money you just can not beat the quality of time you get from your camping efforts. What we have here are the best camping gifts on the planet because they make it easy to go. Also just building and finishing these things can offer a lifetime remembered 'father and son' type bonding experience.