These I found on etsy. If you're into knitting, and not into beading, lots of people sell these on etsy for reasonable prices, like 5 to 7 dollars for a few of them.

If you wanted to make them yourself you just have to mosey on down to the craft store and pick yourself up some split rings, some head pins, and some cool beads.

Even easier, you could just buy the split rings and hang forever single earrings, charms, old keys, or whatever else strikes your fancy, from the split rings. Buy the split rings in a size approppriate to the size knitting needle you use.

Why use boring stitch markers?

BTW...split rings are just like key rings, only smaller.