I made small rosaries based on the design of the Irish Penal Rosary, for the kids in the Confirmation Class I taught. I designed it with a lobster clasp on one end so they could loop it around the rear view mirror in their cars. At least it would be visible, and might make them say a prayer from time to time, if they didn't actually use it as a Rosary, at first. I'm also thinking of making a similar style, that kids could hang on the zipper of their backpacks. They could pray the Rosary on the way to and from school,while sitting in the car, or on a bus.
But I saw another design in which you might be interested. It was a rosary made to be a bracelet; it was the beads and Crucifix strung on memory wire that loops around the wrist, and doesn't come loose! It won't fall off your wrist, and doesn't really hang down at all. I haven't made one yet, but when I do, I'll let you know; you could give it a test drive for me to see if it's practical, if you like.
Thank you! I will PM you my address!