Just a quick note- paracord has a much higher tensile strength than the human neck does. You may or may not prefer another material. Just something to consider.
What about neckties, long hair or rings on fingers? At least an EDC necklace is usually tucked inside your shirt and out of harm's way. I'm not trying to single you out Barbarian but every few months someone creates a thread about EDC necklaces and someone always slams them as being life threatening (without mentioning neckties or long hair).
It's easy enough to use a break free knot for neck carry:
http://www.youtube.com/watch?v=864FSx_cTYQPersonally, I don't think the overhand knot in the above video is strong enough and I use a nail knot instead but basically the same overall principle as shown in the video.
Here's a link to the nail knot.
http://www.animatedknots.com/nailknot/index.php?Categ=fishing&LogoImage=LogoGrog.jpg