While letterboxing is not an actual hand made thing, I think anyone who is interested in the handmade should know about it! I just found out about it from some friends and it is basically geocaching + handmade stamps!! so cool!
All you need is a computer, a hand made stamp (Maya*Made has some great examples, tutorials, and wonderful crafts w/ stamps she has made), and ink pad, and some type of journal or notebook.
Once you visit the website (also here) and find a location near you where a letterbox is hidden you have to go out and find it. Some are harder to find than others, but it's kind of like treasure hunting so it can be a lot of fun! Once you find the box, stamp the logbook inside with your personal stamp and sign your name. Then use the stamp provided in the box and sign your personal notebook to log the letterboxes you've found.