Branch Holder
Brilliant designer Naama Agassi built this simple holder that, when slid onto a branch, turns an ordinary stick into a ready-to-duel sabre. As Agassi explains:

Branch holder is a project based on a childhood memory. Inspired by the childrens ability to make a lot out of nothing, by imagination. The holder is functioning as a bridge, symbolising a way of thinking.

Nice. Now I just need to find someone to challenge. Any takers?