The monkey fist is a great self-defense weapon. However, packing one is awkward in or out of your pocket. There are also the legal ramifications depending on where you live.
Using a belt as a self-defense tool is easy. Take the belt off, grab the tongue and start swinging. Nobody wants to walk into the swinging buckle end of your belt. A belt is a common wear item and only takes a second or two to deploy.
I've made several paracord belts. The latest one is made of 550 paracord with 1/4" hex nuts incorporated into it. The reason for the hex nuts is to add weight to the end of the belt. If you hold the tongue of the belt and swing it there is more weight than the typical monkey fist made with a 1" steel ball. The belt is longer than the lead of most monkey fists and with the swinging motion of the belt an attacker is kept further away. The weight at the end of the belt is distributed over a larger area so the force or strike of the buckle end is not as concentrated compared to the small size and dense weight of the monkey fist. This means it would be less lethal and cause less damage to an attacker but still is a very effective weapon and a easy everyday carry item.
When wearing a belt, it is still a good idea to wear pants of about the right size for your waist. Using your belt to fight off an attacker with pants around your ankles is not practical, a good look or easy. Let's face it, you will do a lot better with your pants up.
Belts for a lot of people are accessory or fashion items. Paracord belts have color and pattern options for about any style. They can be wide or narrow and dolled up with things like hex nuts or other niceties.
Other versions of this belt that are lighter and slimmer can be found at http://paracordgalaxy.com/admin-1455223807/index.php?controller=AdminCmsContent&id_cms=68&updatecms&page=2&token=33d38067cab918198514360c56a90972
I have no idea if there are any laws somewhere that would apply to a belt like this. If used I guess it could be looked at similar to a monkey fist and there are laws regarding monkey fists.
M. Shane Sullivan, Owner and Manager of Paracordgalaxy.com