Okay, this is my cruddy concieved weapon. First of all take a stone (about 1 inch wide, a little less thick) with a hole in it (look around beaches and the like, or just use bolts stuck together) and then take a leather chord, quite thin but not too thin, tie a knot in it then slide it into the hole, so it is secure, and you can wear it around your neck.
This thing is great fun
, if you hit someone with the chord it tends to wrap around their arm, then just twist the chord around the stone once and BLAMMO! They have an arm trap, wear the chord on your middle finger and punch forward, and suddenly you have a telescopic 6th knuckle, not to mention the obvious use of it as a garret. I really love my stone on a string thing.