Actually, I think an abacus ring is a great idea or it could be multiple rings on the same finger where the main benefit is you could keep keep count of something. If you had three rows of small beads, you could theoretically keep track of up to a thousand things, all without a battery and with perfect accuracy. Additionally, you could keep track in a very low profile way if the beads were on the inside of the ring toward the palm of your hand and you manipulated them with your thumb. The beads would have to have a slight friction to them so they stay in place but are still easy to move. But in general I like the idea and it's at least as appealing as the op Casio watch ring.