Suggestions for Functional Jewelry?

szyzyg asks: "I'm getting married and my girlfriend and I have been looking around at rings and not really getting anywhere. I have all sorts of high concepts about what this should represent and I keep coming back to the thought 'nothing which is useless can be truly beautiful'. So I've been fighting with the idea of how to make a ring which has some use beyond simple symbolism... concepts like using magnetic minerals to turn it into a compass, or engraving some sort of measuring mechanism into it. So here's the challenge I'm putting to the Slashdot bright idea machine: How do I make a simple piece of jewelry useful? Someone out there must have better ideas."

Comments

Re:Ring

[Mononoke]

A ring is useful, it tells other guys to bug off or the guy who gave her the ring will come a calling.

Don't you look at a ladies hand, before you start hitting on her?

Yes. It means if we do spend the night together, she'll be out of the way by morning.