It was very easy to create (I made four in less than five mins), and it works like a charm. O.k., maybe not like a charm, since (due to lack of evidence) I strongly suspect charms don't work. I suggest that it works more like a knife or perhaps a finger trap or even a litter box. Something that is very simple yet does its job quite effectively. It's a smidgen more complex than coming up with something for your cat to crap in and a shade or two duller than forging steel and figuring out how to give it an edge. As a matter of fact, I'd put it right on par with getting your finger stuck in a trap.
I made this one to hold my iPod ear buds. I don't know if other brands vary in cord diameter but it also works well with the buds my cell phone came with.
1) Start with a small wooden spool (I got mine for $0.25 at a second hand store. I suspect my mother might have a few for substantially less money). The one I used is 1 1/8" high by 7/8" diameter.
2) I used an 1/8" brad point drill bit and drilled through both spool lips (sorry, I'm ignorant to the anatomy of a spool).
3) Then I used my Dremel with a cutting disk to put a narrow 1/16" slot through the edge of the lip into the center of the 1/8" hole that I had drilled. The slot has to be an iota narrower than the cable of your ear buds to hold them in place properly. More than an iota and that's $0.25 and 75 seconds you'll never get back. Ever.
4) Run the plug through the center of the spool, put the cord through one slot, wrap the cord around the spool and put the ear bud end of the cord through the other slot.
Easy as pie. Except that, let's face it, pie isn't easy. Nor is pi. It takes a good hour to make a pie. And pi? Well, that just goes on forever. So let's say its almost as easy as making a litter box!