In the video, it seems to me that the belt has somehow been attached to his pants in the back to make it appear that it can better hold its position. I didn't notice anything in the article mentioning that, so it appears to be a little misleading....
Marilyn

In the images there is a carabiner at the bottom. Could be hooked into a belt loop.

Marilyn- You are 100% correct as it can be clearly seen in the slow motion handcart that the lower back portion is physically tied to the pant waistband. Everything he is doing would cause that starp as sold to fly off, unless he held in by hand. Very misleading and even if not, not a very good idea in the first palce. Buy a small backpack that wil do the same without a cumbersome item filled strap across your front torso.

It looks like one end of it is a Carabiner you can attach it to a belt loop or watter bottle or something. I'm not sure if I like the idea of the wallet being built into it or not rather than just having a pouch to hold a wallet but it seems like something that would be useful for bicycling where items in your pocket (keys, wallet etc.) limit your movement.
I hate having things in my pockets. But I still think there is a pretty big step between sticking my wallet in one for a bike ride and replacing my wallet with one.
I kind of like the idea though and adding a couple different pocket configurations probably won't be that hard.

It's not karate, it's capoeira.

Pair this with a Utilikilt and you are Good To Go! /sarcasm.
I'm all about storage for my gear, but this is even too nerdy for me.

Pretty sure this is called a Bandoleer and Chewbacca wore one!

I'll stick with a fanny pack.

For designers looking to create something practical, let's not lose sight of the practicality of the fanny/hip pack (just sayin...). The RUNNUR basically takes the 'embarrassing' fanny pack, elongates it and turns it into a hall monitor sash - which is cool too, right? Right. Stylistically, this is probably best used for meter maids giving out citations.

Has everybody forgotten what vests are? Stylish and have those extra needed pockets too.