This is one of many possible variations of a chain sinnet. Here I've made a simple paracord bracelet with it. I did this one without a side release buckle, but one could be easily added. I've seen this sinnet/chain/knot demonstrated in a couple of knot books.
The amount of paracord you'll use will depend on your wrist size, but it seems to work out to less than a foot of cord per inch of bracelet. I'd suggest using a 7 or 8 foot length of paracord to start with for an average sized wrist and you'll see how much you'll actually use depending on how tight/loose you you make the bracelet.
It would also make a decent belt, strap, lanyard, or hatband and if you need to take it apart to use the cord, just remove the last strand that locks it in, and you can pull both ends to unravel it in seconds.
I tried a doubled version of the chain sinnet with some black and neon green paracord. I didn't have enough cord left to try it as a bracelet, so I used what I had for a lanyard. Here's a short video showing the sinnet pulled apart.
Knot tying friend, Ken Cardwell, put up a couple of videos for a tying a chain sinnet paracord bracelet in November of 2009, so I went back and added them to this blog post, since I hadn't done a tutorial myself.