Bored? Why not direct your restless energy into building a Atlatl, an ancient spear-throwing device that'll let you toss a spear far farther than you could before.

Using leverage, this simple device will radically increase your throwing power. Finally, you can deliver messages to your neighbors via notes stuck into their doors with a spear thrown from across the street. That way they'll know you aren't fucking around. [Make via Lifehacker]